Trickster Badgerfolk

Ethnic Feat You learn the spell Disguise Self. Your first cast of this spell each day, does not cost any mana. Additional casts of this spell cost 1 mana. While at 0 mana, you can attempt to cast Disguise Self, Roll a Constitution Saving Throw(DC10) If you succeed, you take 1 point of exhaustion, and the spell is cast as normal. On a fail, you take 2 points of exhaustion and the spell fails.