From Creatures Wikia
Dwarf Norns are naturally smaller versions of the White Haired Pixie Norns made by Markham Carroll for Creatures. They have been gengineered to be good breeders, having genes that raise sex drive in response to hunger and glycotoxin. They occupy norn slot 8, and so will clash with the Wood Norns or Dragon Norns.
The Dwarf Norns are available from Markham's Norn Land, including a set of coloured exports at the oldest site (click the C1 link).