Pig!
First off, it's a great drawing. I'm not going to praise any "technical" details of the drawing, since everything seems fine as usual.
I like the motive, he looks the greediest of your four little piggies, so I assume he is the boss of them. They way you "deformed" his head makes him also look sleazy enough to do the job.
Also very "George Orwell"-ish.