Grendel
An experiment done by the Shee gone wrong. They accidentally created an aggressive and vicious species of creatures, who are the arch-enemies of the Norns.
In Creatures 1 the Grendel is found in a large tree (Yggsdrasil) near one of the oceans; in Creatures 2 it can usually be found near the Volcano, and in Creatures 3 they are generally found in the Jungle Terrarium.
Originally, Albian Grendels were a species reliant on a Queen (the Grendel Mother) for reproduction, however since then the species has become more reproductively active. Known subspecies include the dangerous, hunting, Banshee Grendels created by a subspecies of the Shee themselves, the Banshee.
In Norse Mythology, The Grendel was a monster, which was a descendant of Cain, the first murderer, and eats drunken men. Beowulf defeats him bare-handed. Then the Grendel's mother, who was more powerful than the Grendel itself tries to revenge her son, but is defeated also by Beowulf.