From Creatures Wikia
The Cetus Grendels are a blue tinted aquatic breed made by Grendel Man. The name comes from a gigantic, ocean-going serpent dragon that featured in a Greek Myth. They, although amphibious, prefer the water over land. Over the years of being in the sea, their legs have shrunk over the years of misusage, but are still present. To make up for their atrophied limbs, they swim with the Aquanorn swimmeragent. They eat little vegetation, prefering critters. They also "eat" ettins. This is accomplished through repeated slaps by their extremely small arms. They strongly prefer cold water to warm.
Cetus Grendels can be downloaded from Grendel Man's section at Creatures @ CU7.