In the Bubblegloop Swamp level you need to do a minigame and score 30 points.
First you need to turn yourself in a crocodille. You can do that in the Mumbo hut. You can get there if you follow the road near te big crocodille head and walk on for a few minutes. You need to have 10 mumbo tokens to turn into a mini crocodille.
When that is done go back to the croccidle head and enter it trough his nose. You will find a red croc who wants to play a game. Your best and most easy chance is to get the achivement is in your first turn. Just rush and eat 30 of those red chomps. If you fail don´t worry you can try it as much as you want. Don't forget to use the running shoes to make this easy.