Oh hell yer.
People who do that in real life need to be shot in the head.
I'm going with the Wither on this one. Just starts blasting everything around it like a mad man. I would not want that thing running around in real life.
For me it has to be the enderman followed by the skelly for bone meal.
But I chose the enderman because I love enderpearls way to much.
I saw on once while exploring in BTC's old minecraft server