Give a boy an item which he can use to slam things around:

Set 1: Bat (Sports)
Set 2: Baseball Bat
Set 3: Tennis Racket

Scribblenauts Remix 2-6 Cheats Hints gallery:
2-6-1-a: Help the birthday boy break the pinata!
2-6-1-b: Pinatas break when you hit them.
2-6-1-c: Give the boy something to swing at the pinata.