Answer

Jatasura — Jatasura was a rakshasa who disguised himself as a Brahmin and kidnapped Draupadi and the Pandavas during their forest exile. Bhima fought and killed him to rescue them. This episode is separate from Bhima's quest for the Saugandhika lotus, during which he also encountered Hanuman, but Jatasura's defeat is one of Bhima's celebrated rakshasa-slaying feats of the Vana Parva.