Here are the first two designs for the creature I've been thinking about making. They differ from the ones I originally planned out, but I think they look good this way. I'll make up lifeform profiles for them later once I have three more designs for the species, and once I draw them full-body style.
Also, the Jellyshroom Spined Lizard does have spines, they're just not on the head. Just mentioning that before anyone starts asking.
Art made in MS Paint.