Woof. I didn't know they were THAT dumb, but I believe it!! Thanks for letting me know - I'll keep it in mind with future hides!
Luckily, I'm 99% sure Zuul and Notzuul are both done growing and couldn't get much chubbier! They still fit (barely) through the eye sockets so I think they get to keep their beloved original skull. But again, thank you!!