To be overly:
confused
bored
mad
sad
temptatious
intuned
glad
or excited.
It is used to overly exaggerate that specific feeling.
And no, it DOES NOT literally mean anything. It's an IDIOMATIC EXPRESSION, it does NOT mean that you actually want to punch a babyin the face.
To be so mad and/or frustrated that the only thing that can make your day better is punch a baby or a small child. This level of anger is above Kick a Puppy mad/frustrated. This is the highest level of anger