Bakasur was a rakshasa or demon who was killed by bhima. it lived near the city of chakranagari and had forced the king of that place to send him a large amount of as food and he would also eat the people who carried the food .
After discussion with the Pandavas, it was decided that Bhima would go to Bakasura to save the family and people of Ekachakranagar. Hence, Bhima took the stead of a bait villager and went with supplies to Bakasura. When Bhima reached the forest, he found Bakasura. In order to irritate him, Bhima himself ate all the food. as expected bakasura got very very angry. A fierce battle erupted between the two and finally, Bhima killed Bakasura