Aztec-Mixtec turquoise double-headed snake
Aztec fire serpent
(it's a rattler, see the fangs?)
Aztec rattlesnake,
Crotalus durissus
(the Aztecs did like snakes)
I am not sure what this figure is doing with this snake,
but it's a detail inside a late Egyptian coffin
This Roman-era Egyptian child's coffin
also has a serpent on the lid.
Also Roman, this detail of "Mithras slaying the bull"
shows a dog and snake drinking the blood of the bull
that the god is spilling.