alligator snapper

GNU Webster's 1913

1. n. a very large and voracious turtle (Macrochelys lacertina) inhabiting the rivers of the southern United States. It sometimes reaches the weight of two hundred pounds. Unlike the common snapping turtle, to which the name is sometimes erroneously applied, it has a scaly head and many small scales beneath the tail. This name is sometimes given to other turtles, as to species of Trionyx.

WordNet 3.0

1. n. large species having three ridges on its back; found in southeastern United States