Llamhigyn Y Dwr
The nightmare pictured above is a beastie from Welsh folklore called the Llamhigyn Y Dwr, or Water Leaper. It's given this name for its endearing habit of leaping from lakes, swamps, ponds, rivers, and other bodies of water and sinking its sharp little teeth into unsuspecting victims. Favorite prey of the Llamhigyn Y Dwr include hardworking fisherman, poor benighted sheep wandering too close to muddy banks, and anything else it can catch. The creature's appearance alone is enough to strike victims dead, never mind the cringeworthy screech, or sudden gut-wrenching attacks of this flying toad-bat. As you can see, it has the legless body of a frog, a long creepy tail, and wings that would make a bat proud. The nasty, thrashing, tail has a stinger on the end. When assaulting fishermen, its favored technique is to lurk below water, surge into flight, screech maniacally, snap the fishing line, then drag the terrified men to their deaths and consumption. It's enough to make you think twice about going for a swim.
Don't give me that innocent look!