I hope that this isn't a defect as my golden has it too
I remember when i bought her, all of the other goldens had the bump, and while I thought that it was odd, I just thought that it was just a bone frogs have that's more obvious in this species. I came across this site awhile ago ( Golden Tree Frog [Polypedates leucomystax] - $15.00 : Live Reptiles for Sale from GeneralExotics.com, Healthy and Active Exotic Reptiles Delivered to Your Door! ) and the frog in that picture has the ridge too.
Yeah, Bulbasaur is pretty clumsy herself. She is always hitting her head off of the top of the cageBut I've shown pictures of Luigi before and everyone thinks it was some sort of injury when he was younger (which makes complete sense. He's like a clumsy toddler. He probably has hit his head several times. lol).I would like to get another one just to see if it really is something with the species.