His legendary prowess has been mentioned in glowing terms throughout the epic. Eg: "Of all the wielders of the mace, there is none equal to Bhima; and there is none also who is so skilful a rider of elephants. On car, they say, he yields not to even Arjuna; and as to might of arms, he is equal to ten thousand elephants. Well-trained and active, he who hath again been rendered bitterly hostile, would in anger consume the Dhartarashtras in no time. Always wrathful, and strong of arms, he is not capable of being subdued in battle by even Indra himself." Udyoga Parva Chapt XXII.
He lived for a time in hiding with his brothers during their first exile. In this period, he came across Hidimba and Hidimbi, a rakshasha brother and sister. Because of the enmity of the rakshasha to the people of the Kuru kingdom, Hidimba asked Hidimbi to lure Bhima to a trap. However, Bhima and Hidimbi were attracted to each other. Bhima fought and killed Hidimba, and lived for a year in the forest with Hidimbi, by whom he had a son, Ghatotkacha.
With his brothers, he was married to Draupadi. After the first return of the Pandavas to the Kuru lands, he challenged the king of Magadha, Jarasandha, to a wrestling bout and killed him, thus making it possible for his brothers to take part in the Rajsuya Yajna.
He was furious when the game of dice between his brother, King Yudhisthira, and Duryodhana reached its final stages. But when Dushasana attempted to strip Draupadi in the court, he swore that he would kill him one day and drink his blood.
During the second exile of the Pandavas, he visited Alakapuri and was blessed by Kubera. At the end of their exile at the court of Virata, he disguised himself and acted as a palace cook.
He was a pivotal figure in the great battle of Kurukshetra, killing six out of the eleven akshaukiNis of the other side(Kauravas). Six akshauNis adds up to the astronomical figure of around 1,705,860 men and 787,320 beasts which is testimony to the portrayal as the character of supreme physical prowess. In the battle, his charioteer was Krishna's son himself. During a majority of the 18 days during which the battle was fought, the kauravas were frightened to face his might and sent elephants to fight him. An entire sub-chapter is devoted to describing the "light chat" or banter that he used to maintain with Krishna's son whilst fighting the enemies - yet another glimpse into the power that VedaVyasa invests in Bhima's persona. Bhima's weapon of choice was the mace - which means he was skilled in close combat. Amongst the most important personalities that he quelled were Baka (head of a cannibalistic race), Kirmira ( Baka's brother), MaNiman ( leader of the anger-demons in Kubera's garden), Jarasandha, Dushasana etc. He also defeated mighty Dronacharya by breaking his chariot eight times while Arjuna was trying to find and kill Jayadratha, defeated and forced the powerful Karna to withdraw from battle in four pitched battles while Karna was trying to save the remaining brothers of Duryodhan. During the battle, he killed the elephant called Ashvatthama, which enabled the Pandavas to spread the falsehood that Ashvatthama son of Drona, had been killed. At the end of the battle, he also fatally wounded Duryodhana in a duel, after striking him a foul blow below the waist. At this time, Balarama criticised Bhima for the foul blow, but was calmed down by Krishna. Bhima refrained from killing any respectable elders in the Kaurava's side out of respect for their virtue. The only elderly person he killed was the king of Bahlika (Bhishma's maternal uncle) - and he does this because the king of Bahlika asks Bhima to kill him to release him from the sin of fighting for the kauravas (Bahlika had to fight with the kauravas on account of Bhishma, his nephew).
He finished his days with his brothers and Draupadi, on their great and final journey toward Vaikunta. He was the last to die on the journey, leaving Yudhisthira alone to complete the journey by himself.
Although there are several instances of Arjuna and others doubting or questioning the will of Krishna, the portrayal of Bhima's devotion to krishna is umblemished in the original Mahābhārata.