Someone that has the appearance of a crack head, or who has been taking meth. Their face is all messed up and their hair is like a bird's nest. Also, if the person is acting like a stupid dumbass or doesn't understand what you're saying.
Someone that looks like they've been dropped on the head.
She's acting like a mental baby! I wanna punch her in the face!
Ewww, look at her head! It looks deformed!