It's technically on the chapter "All the pretty horses" but if you're replaying the game, you need to go to chapter "The Return of the Prodigal"
Basically, just press "Y" and then head to the theater.
It's in the first scene of the play, jump on a series of 4 crocodiles but don't jump to the next one until it's closed its mouth. Once you land on land again, the achievement will pop.