Once Upon a Time - S2.E2

Harry needs a green crayon to illustrate his story about a naughty Troll, but he finds Sam unwilling to share her art supplies with him. He goes to Dino World to see if he can track down the materials there, but instead stumbles across the same naughty Troll from his story. The Troll will not let him cross the stream without a magic password, just like in his project. After many unsuccessful guesses Harry realises that a simple “please” goes a long way.