My baby griffin: http://beastkeeper.com/pet/16105

She has the Silly gene, despite the fact that neither of her parents have it. Her mother has Norm and Berserker, and her father has Slow-minded and Berserker. 

I'll check with the father's owner to make sure that they didn't use a Mutagen on him, but I'm pretty sure he didn't because I calculated the possible genes that the babies from him and her could have for future breedings, because they match so well gene wise.

Thanks for reporting.

This happened because of the Degeneration bug which was reported a while ago by RedRarebit here. The bug is fixed.

Sorry for the inconvenience.

Thank you. Double checked her genes, and everything is the way it should be.