There are a couple of dozen subspecies of the Milk Snake (Lampropeltis triangulum), which themselves are species of King Snake (so called since they eat other snake species), native to the Americas from southern Canada to northern South America. The Sinaloan is native to northwestern Mexico. The name Milk Snake derives from a myth that they suck milk from cows at night since they are active at night around barns - but in fact they prey on mice and rats there. The Sinaloan can reach nearly 3 feet long (1 metre).

The Pueblan, also called Campbell's Milk Snake, is native to southern Mexico. Milk Snakes are not venomous and are harmless to humans but several of them look similar to the highly venomous Coral Snakes that also tend to have red and black banding (often with yellow warning colour rather than white). This is known as Batesian mimicry and the confusion is intended in nature to protect them from predators. However, in the human world, it has the opposite effect, since many are killed in the mistaken belief they are venomous.

The Honduran Milk Snake is native to rainforest of Honduras, Nicaragua and northern Costa Rica. One of the larger milk snakes, it can grow to over 4 feet long (1.2 metres) in the wild and to some 5 feet in captivity. Its usual colouring is a red base with white or yellow bands bordered with thick black bands (mimicking a venomous Coral Snake). All three of the above Honduran Milk Snakes are unusual (but not rare) in their colouring: the one on the left with no white/yellow bands (melanistic), the one above centre with no black and the one above right with no black/yellow bands (called "albino" despite the red with white).