If you are looking for revenge on your little brother or sister, why not shoot them with a marshmallow.
From the Company:
You may dress in designer duds and never leave the house without heels. But sometimes you just need to let out your inner child and get out a little aggression. Do it in the most harmless (and tastiest) way possible with our new Marshmallow Shooter! Firing mini-marshmallows over 30 feet in rapid succession, the easy-to-refill magazine holds 20 pieces of ammo at one time for nonstop action -- you'll have enough to softly pelt every one of the family members or coworkers who most deserve it. Alternatively, the Shooter comes equipped with 20 foam pellets that can also be used as ammo. Ah, sweet victory! Mini-marshmallows not included. Ages 8 and up.