The alligator gar bears no relation to alligators, but with its wide, crocodilian head and razor-sharp teeth, it’s easy to see how this giant fish got its name.

The largest of seven known gar species, this megafish has a torpedo-shaped body in olive brown and comes armored with glistening scales. It can grow up to 10 feet long, and historical reports suggest it may grow to weigh nearly 350 pounds. This makes it the largest fish species in North America that spends almost all its time in freshwater. (The white sturgeon is often considered North America’s largest freshwater fish, but it spends substantial time in salt water.)

The prehistoric relatives of the species first appeared 157 million years ago