Altamaha Ha

Altamaha-Ha is the name of the lake monster that is said to inhabit the Altamaha River, tributaries, and marshes near Darien, Georgia. The monster is described somewhat eel-like in appearance, from 10 to 40 feet in length, and 1 to 2 feet in width.

The creature has been reported since the early 1960s, or perhaps even before. It has been sighted many times, frequently varying in length but fairly consistent in shape. This may suggest multiple creatures.

Of course, the name of the creature ending in ha ha may in itself suggest a hoax.

Because the Altamaha-Ha lives in a river it would not technically be a "lake monster", but would instead be a "river monster".