From Creatures Wikia
"Meet Quentin, a gengineered grendel who likes norns. He doesn't constantly hit them like most grendels. In fact, he seems to mostly ignore them! Say goodbye to grendel misery. Quentin is the first of the new grendel breed the Peace Grendels.. once I figure out those egg files, there'll be more like him!
The Peace Grendels: Well, I've figured it out, now, so here for your playing pleasure are the Peace Grendels- A race of grendels that can safely mix with your norns (well, mine seem to get on ok!). This version has been altered to allow the female grendel head to appear in the egg layer agent after installation of patch 2."