Croc can jump on his head to be launched into the air, allowing him to reach places much higher than what he can normally reach.
Unlike Jelly Jumps, Hippo is always in hazardous water, so Hippo's assistance is vital to completing the level.
Croc 2 bio
"Croc's cabbage munching friend really should go and see a dentist. Any pressure on his tender gums makes him scream with pain. Remember kids, regular check-ups are good!"