Well, as far as I'm concerned, Pinkie's body is made of some weird combination of bubble-gum and rubber, so she would probably be able to pull of something like this. Like that one episode of Dexter's Lab where Dexter turned himself into bubble-gum and then shaped himself like his dad.
Lyra: OMFG HUMMAN!!!! I WNNA SOUVENIER!!! -levatates saw- -crazed laughter- -saws hand off- YAY!!! I HAZZ A HAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAANNNNNNNNNNNNNNNNNNNNNNNNNNDDDDDDD!!!