I don't think there are any branches in his/her family tree.

he/she fell outta the stupid tree and hit every branch on the way down.

Looks like he/she has been beat with an ugly stick.

Looks like he/she was in a rake fight and lost.

Busy as a one-armed paper hanger

Hoppin' like a one-legged man in an ass-kicking contest

A dumbass bomb went off in here & left no survivors

if someone cuts you off while driving--> "Hey you #$@!, why don't you pull your head out of your ass and take a breath of oxygen."

The Northern Territory (of Australia) has a strong cattle heritage.

Lots of is "mobs", more is "big mobs" and more again is "biggest mobs".

It comes up in regular conversation, so it's deeply rooted in the culture.

Dumb as a bag of hair

and he/she appears to have fallen out of the ugly tree.....and hit every branch on the way down.