brown horse wearing a costume
black and tan hat on horse
a beat-up straw hat on the horse's head
Horse has hankie over nose.
Horse wearing straw hat.
Horse is wearing a lei around neck.
Straw hat is black.
a hat on a head 
a head of a horse 
a horse with lots of stuff in its head 
a person wearing pink sunglasses and a green sombrero is standing next to a brown horse with a pink hat on it'its head