The Winter Soldier and Captain America.

Frost-man has the helmet. America-man steps on the rock. Frost-man points a gun at him.

A guy with gold horns about to shoot america?

I think it's Kurloz or Gamzee, with a word in red blood sating "sHoOt" and words in purple blood saying "aMeRiCa"

The craziest homie in town

A green-faced duck wearing a hat as a hat. And enjoying it.

bird loves hat

Bird sees small brown bat and falls in love instantly.

The duck quite likes the stingray.