Fight monsters and resources. The materials used in the formula of Hippo Bouncer are: -5 crystal bones, -5 mechanical parts and -5 steel. These materials can only be obtained by fighting monsters and resources. How to get the jumpers: Get rid of all the weapons and mow the grass with your bare hands, so the chances of getting the hippopotamus jumpers are higher. There is a certain chance of blowing up the hippopotamus jumpers when playing with crystals at dusk, but they are all random, depending on luck.