Barnacle (Marvel Comics)

Mortimer Everett, also known as Barnacle, is a character from the Marvel franchise. He is a mutant who gained his powers from genetic mutaiton.

Powers
Moisture Solidification: Barnacle is a mutant with the ability to initiate a chemical reaction that turns moisture into a solid shell, containing someone within a constrictive carapace with their own bodily fluids. This also provides him with indestructible armor and the ability to spray through the air a stream of hardened barnacle crust, most likely derived from the moisture in his own body.