Shellder is a water type Pokemon that is the pre-evolved form of the Cloyster. It's a bivalve (2-part shells) creature that constantly stick its toungue out at mainly uses it for burrowing.
Shellder's shell is said to be harder than a diamond, which gives him plenty of protection from other Pokemon's blunt force attacks. Shellder is also critical in the evolution of another Pokemon, Slowpoke. When Shellder bites the Slowpoke's tail, they evolve into a single Pokemon, Slowbro.
Icthus7 provides you two options for the insides on this Shellder papercraft, you have black, which is the common version, and a white one.