Is there any animal (depoisoned) a human can't eat/digest?

Question

Is there any animal (depoisoned) a human can't eat/digest?

Answer 1

sea gulls

I do not think anyone has eaten a sea gull.

Answer 2

A turtle - since their shells are part of their body, and not an attachment, a turtle is technically the cute little thing inside along with the shell.

I'd like to see someone eat a turtle shell and try to p**p it out. Ouch!

Answer 3

Maybe a sand dollar, although apparently we've found ways to eat sea urchins.  Huh... who knew!