Llamhigyn y Dŵr (Welsh for 'Water Leaper') is an evil creature from Welshfolklore that lived in swamps and ponds.[1]
It is described as a giant frog with a bat's wings and zero legs whatsoever, and a long, lizard-like tail with a stinger at the end. It jumps across the water using its wings, hence its name.
It was blamed for problems ranging from snapping fishing lines to eating livestock or even fishermen.[1]
Katharine Briggs, An Encyclopedia of Fairies, Hobgoblins, Brownies, Boogies, and Other Supernatural Creatures, "Llamhigyn Y Dwr", p270. ISBN0-394-73467-X