Karna was one of the biggest liars in Mahabharata!

Many people (specifically the Karna fans) think that he never uttered a single untruth or lie. That karna never failed to keep his promises. That karna always accomplished his vows. But in actuality the reality and truth is much different from what the majority believe. From what is shown on TV serials. His word meant nothing. He was all bark no bite. Karna was a bragger, he was all talk.

1. All of Karna's lies. Exposing at-least 18 of his lies.
1. Karna said that he would never do anything disagreeable to Duryodhana 
1. Quote: Karna said, 'I will not do anything that is disagreeable to Dhritarashtra's son, O Kesava. Devoted to Duryodhana's good, know that I have cast off my life (for him). http://sacred-texts.com/hin/m06/m06043.htm - (Chapter linK)
1. Yet he gave Kunti the lives of 4 Pandavas including Bhima who kills Duryodhana's brothers.
2. Karna said that he would make porcupines out of the Pandavas with his arrows (on the 14th night).
1. Karna's words
1. Quote: Amongst all the Parthas, Phalguna is the strongest. At him I will hurl the fatal dart of Sakra's workmanship. Upon the death of that great bowman, his brothers, O giver of honour, will either surrender themselves unto thee or once more retire into the forest. When I am alive, O Kauravya, never indulge in any grief. I will vanquish in battle all the Pandavas united together and all the Panchalas, the Kaikeyas, and the Vrishnis assembled together. Making porcupines of them by means of my arrowy showers, I will give thee the earth.'
2. Link: http://sacred-texts.com/hin/m07/m07154.htm
2. But instead he fled from just one Pandava (Arjuna)
1. Quote: Then the mighty bowman Partha, beholding Karna's prowess, quickly cut of the latter's bow at the handle. And he also despatched the four steeds of the Suta's son to Yama's abode with a number of broad-headed shafts. And that scorcher of foes also cut off from the trunk the head of Karna's driver. Then, the son of Pandu and Pritha pierced the bowless, the steedless, and the driverless Karna with four shafts. Then that bull among men Karna, afflicted with those shafts, specially jumping down from that steedless car, mounted upon that of Kripa. Beholding the son of Radha vanquished, thy, warriors, O bull of Bharata's race, fled away in all directions.
2. Link: http://sacred-texts.com/hin/m07/m07155.htm
3. Karna could not save his charioteer from being made into a porcupine by Arjuna's arrows.
3. Karna lied to Shalya that Indra was the bug who bit him: On that occasion, O Shalya, the chief of the gods, wishing to benefit Phalguna, caused an obstacle, by approaching my thigh and piercing it, having assumed the dire form of a worm. http://www.sacred-texts.com/hin/m08/m08042.htm - (Chapter Link)
1. He was clearly lying as the bug was not the chief of the gods but actually a Rakshasa when the actual event occurred! Description of actual event: As soon as Rama cast his, eyes on it, the worm gave up its life-breath, melting in that blood which it had drawn. All this seemed wonderful. Then in the welkin was seen a Rakshasa of terrible form, dark in hue, of a red neck, capable of assuming any form at wilt, and staying on the clouds,--his object fulfilled, the Rakshasa, with joined hands, addressed Rama, saying, 'O best of ascetics, thou hast rescued me from this hell! Blessed be thou, I adore thee, thou hast done me good!' Possessed of great energy, the mighty-armed son of Jamadagni said unto him, 'Who art thou? And why also didst thou fall into hell? Tell me all about it.' He answered, 'Formerly I was a great Asura of the name of Dansa. In the Krita period, O sire, I was of the same age with Bhrigu. I ravished the dearly-loved spouse of that sage. Through his curse I felt down on the earth in the form of a worm. In anger thy ancestors said unto me, 'Subsisting on urine and phlegm, O wretch, thou shalt lead a life of hell.' I then besought him, saying, 'When, O Brahmana, shall this curse end?' Bhrigu replied unto me, saying. 'This curse shall end through Rama of my race. It was for this that I had obtained such a course of p. 6 life like one of uncleansed soul. O righteous one, by thee, however, I have been rescued from that sinful life.' Having said these words, the great Asura, bending his head unto Rama went away. http://www.sacred-texts.com/hin/m12/m12a003.htm - (Chapter Link)
4. Karna lied to soldiers that he would protect women
1. But when the time and place came to save a woman (Draupadi) he never did save her or protect her from anything at all.
1. Quote: I shall either slay all my foes united together, or slain by them proceed to the regions reserved for heroes. O charioteer, I know that even this is what I should do, when women and children cry for help, or when Duryodhana's prowess sustains a check.
2. Source: http://sacred-texts.com/hin/m07/m07002.htm
2. When the time came to save Duryodhana's wife from the Gandharva's he (Karna) did not protect the woman at all.
1. I don't need a quote or source (Mahabharata) for this one. We all know what that Gandharva did to Karna they broke his chariot, they wounded him, mangled his body and made him flee from the battlegrounds. Leaving behind the ladies of his friend Duryodhana.
5. Karna lied to Parshuram that he was a Brahmana of Bhrigu's race. 

1. Quote: When Drona had answered thus, Karna, having worshipped him, obtained his leave, and proceeded without delay to Rama then residing on the Mahendra mountains. Approaching Rama, he bent his head unto him and said, 'I am a Brahmana of Bhrigu's race.' This procured honour for him. With this knowledge about his birth and family, Rama received him kindly and said, 'Thou art welcome!' at which Karna became highly glad. http://www.sacred-texts.com/hin/m12/m12a002.htm - (Chapter Link)

1. Karna confesses to the truth when he gets caught lying: Thus asked, Karna, fearing to be cursed, and seeking to gratify him, said these words, 'O thou of Bhrigu's race, know me for a Suta, a race that has sprung from the intermixture of Brahmanas with Kshatriyas. People call me Karna the son of Radha. O thou of Bhrigu's race, be gratified with my poor self that has acted from the desire of obtaining weapons. There is no doubt in this that a reverend preceptor in the Vedas and other branches of knowledge is one's father. It was for this that I introduced myself to thee as a person of thy own race.' http://www.sacred-texts.com/hin/m12/m12a003.htm - (Chapter Link)
6. Karna lied to Shalya saying that he had no fear of the two Krishnas (Arjuna & Krishna): Knowing as I do my own might, I do not cherish any fear of the two Krishnas. http://www.sacred-texts.com/hin/m08/m08040.htm - (Chapter Link)
1. Yet fear encased him
7. Karna lied in the Swayamvara that only Indra, Vishnu, Drona and Arjuna are capable of fighting with him when he is angry: Then addressing his antagonist, Karna said, 'O thou foremost of Brahmanas, I am gratified to observe the energy of thy arms that knoweth no relaxation in battle and thy weapons themselves fit for achieving victory. Art thou the embodiment of the science of weapons, or art thou Rama that best of Brahmanas, or Indra himself, or Indra's younger brother Vishnu called also Achyuta, who for disguising himself hath assumed the form of a Brahmana and mustering such energy of arms fighteth with me? No other person except the husband himself of Sachi or Kiriti, the son of Pandu, is capable of fighting with me when I am angry on the field of battle.' http://www.sacred-texts.com/hin/m01/m01193.htm - (Chapter Link)
1. During the 14th night battle of the Kurukshetra war Karna was enraged because he thought his son was dead yet he was still losing a fight with even a disciple of Arjuna even though he was angry: Then Karna, believing that mighty car-warrior, viz., Vrishasena, slain, became scorched with grief on account of the death of his son and began to afflict Satyaki with great force. Thus afflicted by Karna, the mighty car-warrior Yuyudhana, with great speed, repeatedly pierced Karna with many shafts. Once more piercing Karna with ten arrows, and Vrishasena with five, the Satwata hero cut off the leathern fences and the bows of both sire and son. http://www.sacred-texts.com/hin/m07/m07167.htm - (Chapter Link)
8. Karna said that Arjuna was not even equal to 1/16th part of him: Hearing these words, Karna said, 'You always censure us by speaking on the virtues of Falguna, Arjuna, however, is p. 72 not equal to even a full sixteenth part of myself or Duryodhana!' http://www.sacred-texts.com/hin/m04/m04039.htm - (Chapter Link)
1. Over here Karna also said that no person is capable of fighting him when he is angry except for Arjuna: No other person except the husband himself of Sachi or Kiriti, the son of Pandu, is capable of fighting with me when I am angry on the field of battle.' http://www.sacred-texts.com/hin/m01/m01193.htm - (Chapter Link)
9. Karna lied to Duryodhana that he would slay partha in the sight of Bhishma: 'Do not grieve, O chief of the Bharata. Even I will do what is agreeable to thee. Let Santanu's son Bhishma soon withdraw from the great battle. After Ganga's son will have withdrawn from the fight and laid aside his weapons, I will slay the Partha along with all the Somakas, in the very sight of Bhishma. http://www.sacred-texts.com/hin/m06/m06098.htm - (Chapter Link)
1. Karna already vowed to not fight when Bhishma is still alive. How can he fight in the very sight of Bhishma if Bhishma is not alive?: "Karna said, 'As long as Ganga's son liveth, O king, I shall never fight. After Bhishma is slain, I shall fight with the wielder of Gandiva.' http://www.sacred-texts.com/hin/m05/m05157.htm - (Chapter Link)
10. Karna lied that he would give up even his life for Duryodhana's sake: I am unable to transgress my destiny. The son of Vichitravirya's son is, O king, always engaged in doing me good. For the accomplishment of his purpose, I will cast away my life-breaths that are so dear, and this body that is so difficult of being cast away. http://www.sacred-texts.com/hin/m08/m08037.htm - (Chapter Link)
1. Yet when Duryodhana was at the mercy of Gandharvas, Karna did not cast off his life and instead fled away from the scene: As regards myself, assailed by all the Gandharvas, I fled before thy eyes, unable to rally our flying host. Assailed by the foe with all his might, my body mangled with their arrows, I sought safety in flight. http://www.sacred-texts.com/hin/m03/m03245.htm - (Chapter Link)
11. Karna lied to Bhima (on the 14th day of Kurukshetra) that he was unable to bear the burden of battle: And Karna said, 'Without skin in weapons, do not fight with me. Thou art but a child, a laggard in battle! http://www.sacred-texts.com/hin/m07/m07135.htm - (Chapter Link)
1. Karna later on confesses that Bhima is superior to all: This Vrikodara is brave and is a hero full of wrath. He is reckless in protecting his body, and in strength of limbs he is superior to all. http://www.sacred-texts.com/hin/m08/m08050.htm  - (Chapter Link)
12. Karna lied when he said that Arjuna will shoot shafts at him mildly: Having been engaged in ascetic austerities for the (last) eight and five years, Vibhatsu will strike me but mildly in this conflict, and the son of Kunti having become a Brahmana endued with good qualities, hath thus become a fit person to quietly receive shafts by thousands shot by me. http://www.sacred-texts.com/hin/m04/m04048.htm - (Chapter Link)
1. Arjuna struck Karna violently: And taking another sharp and blazing arrow endued with great energy, the mighty son of Kunti pierced the breast of Kama. And that arrow, cleaving through his mail, penetrated into his body. And at this, Karna's vision was obscured and his senses left him. http://www.sacred-texts.com/hin/m04/m04060.htm - (Chapter Link)
13. Karna lied to Shalya that Shalya utters many disagreeable speeches about the Pandavas: Like a fool thou hast, for the sake of Pandu's son, rebuked me and told me many disagreeable things. http://www.sacred-texts.com/hin/m08/m08042.htm - (Chapter Link)
1. Yet Karna later on says everything Shalya uttered was true: "Sanjaya continued, 'While the ruler of the Madras was saying these words unto the son of Radha, Vrikodara, excited with rage, came upon Karna. Beholding Bhima, that delighter in battle, approaching him in that way, the son of Radha laughingly said unto Shalya these words, "The words that thou, O ruler of the Madras, hast today spoken to me regarding Bhima, O lord, are without doubt all true. http://www.sacred-texts.com/hin/m08/m08050.htm  - (Chapter Link)
14. Karna lied to Arjuna that he would never be filled with anxiety whenever he encounters him in battle: O Pritha's son, if Sakra himself fight on thy side, still I would feel no p. 106 anxiety in putting forth my prowess. Thy wish, O son of Kunti, is about to be gratified. http://www.sacred-texts.com/hin/m04/m04060.htm - (Chapter Link)
1. Yet on the 17th day of Kurukshetra: When his car began to reel from the curse of the Brahmana, and when the high weapon he had obtained from Rama no longer shone in him through inward light, and when his terrible snake-mouthed shaft also had been cut off by Partha, Karna became filled with melancholy. http://www.sacred-texts.com/hin/m08/m08090.htm - (Chapter Link)
1. Melancholy is a Synonym of Anxiety.
15. Karna lied to Bhishma that he would kill the Pandavas: 'As long as thou livest, O thou of Kuru's race, I will never fight! if thou, however, succeedest in slaying the sons of Pandu in great battle, I shall, O Kaurava, with Duryodhana's permission, retire into the woods. If, on the other hand, thou, O Bhishma, slain by the Pandavas, attainest to heaven, I shall then, on a single car, slay all of them, whom thou regardest as great car-warriors.' Having said this, mighty-armed Karna of great fame, with thy son's approval, did not fight for the first ten days. http://www.sacred-texts.com/hin/m07/m07001.htm - (Chapter Link)
1. Before this incident Karna had promised Kunti that he would spare the lives of four out of the five Pandavas: Except Arjuna, thy other sons, Yudhishthira, Bhima, and the twins, though capable of being withstood by me in tight and capable also of being p. 282 slain, shall not yet be slain by me. http://www.sacred-texts.com/hin/m05/m05146.htm - (Chapter Link) 
16. Karna lied to Indra that he could not part with his Armour and earrings
1. Quote: I desire, O chastiser of foes, that thou mayst speedily give me these; for, this one gain of mine will be considered as superior to every other gain!' Hearing these words, Kama, said, 'O Brahmana, I will give thee homestead land, and fair damsels, and kine, and fields; but my mail and ear-rings I am unable to give thee!
2. Link: http://sacred-texts.com/hin/m03/m03308.htm
3. Yet Karna still gives it to him
1. Quote: And Karna cutting off the excellent mail from his person, gave it to Vasava, still dripping. And cutting off his ear-rings also from off his ears, he made them over to Indra. 
2. Link: http://sacred-texts.com/hin/m03/m03308.htm
17. Karna lied that he would kill the grandsons of the Pandavas
1. Quote: I have that weapon with me still, and my period is not yet run. I am, therefore, fully competent (to win victory) Let the responsibility be mine. Having obtained the favour of that Rishi, I will slay within the twinkling of an eye the Panchalas, the Karushas, the Matsyas, and the sons of Pritha with their sons and grandsons, and bestow on p. 143
   thee numerous regions won by my weapons.
2. Source: http://sacred-texts.com/hin/m05/m05062.htm
1. Karna failed to slay a single grandson of the Pandava family. Everyone who has read the Mahabharata knows this by now.
18. Karna lied to Shalya that a person like him would neve rbecoem a crook warrior
1. Quote: Endued with great activity, the Suta's son, with eyes burning in wrath, then said unto the ruler of the Madras, "O Shalya, Karna never aimeth an arrow twice. Persons like us never become crooked warriors." Having said these words, Karna, with great care, let off that shaft which he had worshipped for many long years. 
2. Link - http://www.sacred-texts.com/hin/m08/m08090.htm
1. Yet Karna became a crooked warrior when he attacked Abhimanyu from behind (while the latter was shooting shafts at other warriors). 
2. Karna ambushed Dhrishtadyumna on the 14th night with six other car-warriors. It was a group attack 7 on 1. Completely unfair.
3. Karna killed his own troops while fighting Bhima on the 14th day.
4. Karna begged Aswathamman, kripa, Sakuni, Kritavarman etc to wound and weaken and mangle Arjuna & krishna deeply so they would be weakened before the final fight.
5. It was on Karna's counsels that prince Duryodhana poisoned Mighty Bheema when the former was unable to handle the latter's strength.
1. Karna was a crooked warrior, he was a cheat, it is in his nature.
2. All of Karna's failed promises.
1. Karna promised that he would hurl the Vasavi dart only on Arjuna: Addressing Karna, they used to say, 'O Karna. O great bowman, O thou of immeasurable prowess in battle, O foremost of all victors, this dart should not be hurled at any one else than that great car-warrior, viz., Kunti's son, Partha or Dhananjaya. He is the most celebrated amongst p. 424 them, like Vasava amongst the gods. He being slain, all the other Pandavas with the Srinjayas will be heartless like fireless celestials! 1' Karna having assented to this, saying 'So be it' (the desire of) slaughtering the wielder of Gandiva, O bull amongst the Sinis, was ever present in Karna's heart. http://www.sacred-texts.com/hin/m07/m07179.htm - (Chapter Link)
1. But he launches it on Ghatotkaca instead: Indeed, that dart, O king, which he had kept and adored for years for (achieving) the slaughter of Pandu's son in battle, that foremost of darts which Sakra himself had given to the Suta's son in exchange for the latter's ear-rings, that blazing and terrible missile twined with strings and which seemed to thirst for blood, that fierce weapon which looked like the very tongue of the Destroyer or the sister of Death himself, that terrible and effulgent dart, Naikartana, was now hurled at the Rakshasa. http://www.sacred-texts.com/hin/m07/m07176.htm - (Chapter Link)
2. Karna promised that he would save Jayadratha's life: I shall strive my best so that this foremost one of the sons of Pandu may not succeed in slaying the ruler of the Sindhus. As long as I shall fight, shooting my whetted shafts, the heroic Dhananjaya, capable of drawing the bow with even his left hand, will not succeed in getting at the ruler of the Sindhus. http://www.sacred-texts.com/hin/m07/m07141.htm - (Chapter Link)
1. But he failed in doing so: That shaft, sped from Gandiva, coursing swiftly, snatched Jayadratha's head away, like a hawk snatching away a smaller bird from the top of a tree. http://www.sacred-texts.com/hin/m07/m07142.htm - (Chapter Link)
3. Karna promised that he would slay Arjuna in Virata Parva: With golden arrows furnished with vulturine wings shot on all sides, let the firmament seem today to swarm with fire-flies. Slaying Arjuna in battle, I will discharge today that debt, difficult of repayments, but promised of old by me unto Dhritarashtra's son. http://www.sacred-texts.com/hin/m04/m04048.htm - (Chapter Link)
1. Instead he runs away after getting pierced by Arjuna: And mangled and afflicted by the arrows shot by Partha the son of Pandu, Vikartana's son, quitted the van of battle, and quickly took to flight, like one elephant vanquished by another.'" http://www.sacred-texts.com/hin/m04/m04054.htm - (Chapter Link)
4. Karna promised Arjuna that he would surpass the performance of Arjuna: And that foremost of eloquent men, the offspring of the Sun, in a voice deep as that of the clouds, addressed his unknown brother, the son of the subduer p. 288 of the Asura, Paka (Indra), saying, 'O Partha, I shall perform feats before this gazing multitude; excelling all thou hast performed! Beholding them, thou shall be amazed.' http://www.sacred-texts.com/hin/m01/m01139.htm - (Chapter link)
1. But he only equaled Arjuna's performance: Then with the permission of Drona, the mighty Karna, delighting in battle, there did all that Partha had done before. http://www.sacred-texts.com/hin/m01/m01139.htm - (Chapter link)
5. Karna made a promise to protect any women
1. Quote: I shall either slay all my foes united together, or slain by them proceed to the regions reserved for heroes. O charioteer, I know that even this is what I should do, when women and children cry for help, or when Duryodhana's prowess sustains a check.
1. Source: http://sacred-texts.com/hin/m07/m07002.htm
2. But he failed to keep this promise when he saw a woman (Draupadi) being assaulted.
3. Karna himself joins in on the assault against the woman (Draupadi).
3. Opinion of other great personalities and characters on the authenticity of Karna's word.
1. Aswathamman the classmate of Karna, they both learned from Kripa and Drona.
1. "Aswatthaman said, 'The kine, O Karna, have not yet been won, nor have they yet crossed the boundary (of their owner's dominions), nor have they yet reached Hastinapura. Why dost thou, therefore, boast of thyself? Having won numerous battles, and acquired enormous wealth, and vanquished hostile hosts, men of true heroism speak not a word of their prowess. Fire burneth mutely and mutely doth the sun shine. Mutely also doth the Earth bear creatures, both mobile and immobile. The Self-existent hath sanctioned such offices for the four orders that having recourse to them each may acquire wealth without being censurable. http://www.sacred-texts.com/hin/m04/m04050.htm - (Chapter Link)
2. Of wicked understanding as thou art, thou rebukest, however, my brave uncle from malice. Possessed with pride and insolence, thou braggest today of thy prowess, not regarding any of the world's bowmen in battle! http://www.sacred-texts.com/hin/m07/m07155.htm - (Chapter Link)
2. Shalya the charioteer of Karna, who guided Karna on his glorious last day: 
1. "Forbear, forbear, O Karna, from such bragging. Thou art in transports of delight and sayest what thou shouldst never say. Where is Dhananjaya, that foremost of men, and where again, art thou, O lowest of men?" http://www.sacred-texts.com/hin/m08/m08037.htm - (Chapter Link)
1. Karna chose Shalya as his charioteer (Karna to Duryodhana): Though inferior to Arjuna in respect of these things, I still desire to fight with him. This Shalya, however, the ornament of assemblies, is equal to Saurin. If he becomes my driver, victory will certainly be thine. Let Shalya, therefore, who is incapable of being resisted by foes be the driver of my car. Let a large number of carts bear my long shafts and those that are winged with vulturine feathers. Let a number of foremost cars, O monarch, with excellent steeds yoked unto them, always follow me, O bull of Bharata's race. By these arrangements I will, as regards the qualities mentioned, be superior to Arjuna. Shalya is superior to Krishna, and I am superior to Arjuna. http://www.sacred-texts.com/hin/m08/m08031.htm - (Chapter Link)
3. Kunti the mother of Karna. What mother does not know her son?
1. Kunti considered Karna a deluded person: There is only this sinful Karna then, of deluded understanding and ever following the deluded lead of the wicked Duryodhana, that hateth the Pandavas. http://www.sacred-texts.com/hin/m05/m05144.htm - (Chapter Link)
4. Kripa a guru of Karna who trained him in the science of warfare.
1. Incident 1: "Kripa said, 'O Radheya, thy crooked heart always inclineth to war. Thou knowest not the true nature of things; nor dost thou take into account their after-consequences. There are various kinds of expedients inferrable from the scriptures. Of these, a battle hath been regarded by those acquainted with the past, as the most sinful. It is only when time and place are favourable that military operations can lead to success. In the present instance, however, the time being unfavourable, no good results will be deprived. A display of prowess in proper time and place becometh beneficial. It is by the favourableness or otherwise (of time and place) that the opportuneness of an act is determined. Learned men can never act according to the ideas of a car-maker. http://www.sacred-texts.com/hin/m04/m04049.htm - (Chapter Link)
2. Incident 2: Kripa, the mighty armed son of Saradwat, smiling the while, addressed the Suta's son in these words, 'Thy speech is fair, O Karna! If words alone could lead to success, then with thee, O son of Radha, as his protector, this bull among the Kurus would be considered to have the amplest measure of protection. Thou boastest much, O Karna, in the presence of the Kuru chief, but thy prowess is seldom witnessed, nor, indeed, any result (of thy boastful speeches). Many a time have we seen thee encounter the sons of Pandu in battle. On every one of those occasions, O Suta's son, thou hast been vanquished by the Pandavas. http://www.sacred-texts.com/hin/m07/m07154.htm - (Chapter Link)
3. Incident 3: Thou indulgest in too much brag, O Suta's son! Engage thyself in battle without saying anything. To Put forth prowess without indulging in brag is the duty of good men. Ever roaring aloud, O Suta's son like the dry clouds of autumn, thou showest p. 360 thyself, O Karna to be without substance. The king, however, does not understand it. Thou roarest, O son of Radha, as long as thou seest not the son of Pritha. These thy roars disappear when thou seest Partha near. Indeed, thou roarest as long as thou art out of the range of Phalguna's shafts. http://www.sacred-texts.com/hin/m07/m07154.htm - (Chapter Link)

Another name of Karna can be CHOOT PUTRA.