The doodle or die emblem. But with bones instead of pencils, and they're under the skull... And one of the bones is transparent.
skull and death
Semi-human skull with three "teeth" in the upper jaw and the lower jaw missing.
skull missing its lower jaw
A sweaty skull without a jaw.
the polarity of mushrooms
elements
the avatar showing off elements
Aang is confused
Doodle or Die is the game of "telephone" with drawing!