This is a head-base that can be used to build a puppet-, plushie-, robot- or a fursuit-head (costume). I did not add ventilation holes as I expect most people will not cover the surface with fabric or felt.
I got some inspiration for this model for the old Teenage Mutant Ninja Turtles movies. I did not try to model a specific character.
The model is scaled for costume size (it's sized for normal-sized heads - too big for me - I have a small head) - rescale it if you need to.