Complex sentence: Bugs keeps running when he was frightened until the door on the floor opens and a rock fall down there and there are crocodiles swimming around, he was walking backwards and praying to jump over the crocodiles, until he bumped into Rudolph.
Split into simpler sentences: Bugs keeps running while he is frightened until a door on the floor opens and a rock falls down there and there are crocodiles swimming around. While he is walking backwards and praying to jump over the crocodiles, he bumps into Rudolph.