I'm pretty sure that the Cranwelli X Cornuta (Fantasy) hybrids are infertile. But Cranwelli and Ornata are closer genetically so they might be fertile. That peppermint horned frog on that website sure looks interesting, It has similar markings as a cranwelli but has a brighter green color like an ornata.

http://www.youtube.com/watch?v=3JkU5SRIrwg