Jatasura killed

Yudhistira said - It seems death has called you, and this is why you have come here. One who acts violently towards those who practice non violence always get punished. You are spoiling your own virtues by committing heinous acts.
Draupadi started calling out to Krishna for help. Then she started out to Bhima to come and help.
Bhima was far when he heard the cries. He recognized the voice of Draupadi and rushed to help.

Seeing the rakshasa carrying them, Bhima said Do not worry, I will kill this rakshasa soon.
Bhima uprooted a tree. Seeing that the rakshasa increased his speed. Bhima flung the tree which hit the asura on his head. In pain, the rakshasa released Yudhistira and the others and caught Bhima. With one hand he caught a tree, uprooted that and hit Bhima on his head. On touching Bhima's head, the tree broke. Bhima with his fist, punched the rakshasa hard, on his chest. In pain, the rakshasa released Bhima. The two began wrestling. Taking an opportunity, Bhima sat on Jatasura's chest and caught his neck. Using his feet, Bhima crushed the head of the rakshasa.

With the rakshasa dead, Bhima returned back to the mountain with all. 

Jatasura captures Yudhistira

One day, Bhima had gone inside the forest to hunt. The priest Dhaumya had gone for a bath and the sage Lomesh had gone inside the forest to get flowers. Yudhistira, Nakula , Sahadeva and Draupadi were alone. At that time, Jatasura came there. Jatasura was a friend of Bakasura and thus considered the Pandavas his enemies. Afraid of Bhima, he did not venture near the Pandavas. Seeing an opportunity, the rakshasa approached Yudhistira and said Hidimb and Baka were my dear friends. Your brother Bhima killed them. I have spending sleepless nights, thinking how to tackle you.Today I see the four of you, with Bhima and Arjuna not there to protect you. Bhima and Arjuna will die when they hear you are dead.

Saying this, the rakshasa captured the four and rose skywards.