This has got to be one of the strangest fish landed this year. Anglers Justin Jordan and Terrell Maguire recently hooked into an all-black specimen they say is a melanistic alligator gar. Jordan is a guide for Lotus Guide Service and posted pictures of the unlikely catch on Facebook on May 16.

“Well, Terrell and I found out melanistic gar do exist yesterday,” he wrote. Maguire was the one behind the rod, according to Newsweek. The duo was fishing at a marsh in southeast Texas. Jordan’s pictures show the characteristic bony beak of an alligator gar— but the fish isn’t the grey-green color typical of the species. Instead, it’s jet black, except for the pale flesh on the inside of its mouth. In a comment on the Facebook post, Dorothy Ebers called the fish “freaking scary,” while commenter John Truax said it looked like a creature from the movie Alien.

The fish likely has a recessive condition that is caused by the over-development of melanin in the skin. This turns animals partially or completely black. It’s not known exactly how common melanism is in the wild, but it’s considered to be a rare genetic disorder. Melanism is distinct from albinism, which is the total lack of pigmentation, and leucism, which leads to reduced pigmentation. Leucism and albinism have been observed in wild fish, though they are also rare genetic conditions. This spring, a catfish angler in Tennessee caught an all-white albino catfish on the Tennessee River. Last fall, an angler caught a strange-looking leucistic catfish on the Mississippi River.

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Alligator gar are the largest known species of gar, according to National Geographic. The species can grow up to 10 feet long and weigh close to 300 pounds, making them one of the biggest freshwater fish in North America, second only to white sturgeon. Prehistoric relatives of alligator gar first appeared around 157 million years ago. Today, alligator gar primarily inhabit the waters of the southeast U.S. and Texas.