A sky snake
The sky snake was a large predatory animal native to the planet Areolus. It could fly using two pairs of wings, and bore a rattle on the end of its tail like an Earth rattlesnake. The Areore were wary of sky snake, as they had no treatment for its fast-acting venom, and none of them had ever survived a sky snake attack.
In 2381, Rawda warned Peanut Hamper about the danger of sky snakes. Peanut Hamper mocked the name "sky snake", calling it redundant since all animals on the planet could fly.
Later that year, Rawda's father Kaltorus was fatally envenomed by a sky snake. Though he was resigned to his death as part of the "Great Circle", Peanut Hamper saved his life with a hypospray of antivenom. (LD: "A Mathematically Perfect Redemption")
A sky snake was among the dangerous lifeforms kept in Narj's Miraculous Menagerarium in 2381. (LD: "I Have No Bones Yet I Must Flee")