David Donahue had a nice flapping-ear elephant model. Around 2006 or 2007, I beta-tested the Dumbo action model that Sy Chen was working on while at OUSA. Just the other day, I also saw this flapping-eared elephant on FB. It's always been a cool concept.
Tried to fold and launch this rocket, using a straw and wasn't too successful.
There are other rocket designs, similar to this (you can find a lot of vids on YouTube)- really, you can make up your own waterbomb base variant.
Maybe instead of a straw, I could use Jeremy Shafer's Ninja blow dart and have an origami RPG?