Shane Prigmore designed many of the creatures in The Croods along with Carter Goodrich, Takao Noguchi, and Shannon Tindle. He has worked on other Dreamworks films, too, including How to Train Your Dragon and Rise of the Guardians. Some of Shane’s development work on Rise of the Guardians is posted on his blog, with a few examples below. Here is an interview with Shane from the Character Design blog. It includes some earlier personal work and designs from movies such as Coraline.