Skull Bash is a Normal-type move that is learned by several Pokémon, including:
* Snorlax (levels up)
* Mamoswine (levels up)
* Golurk (levels up)
* Rhyperior (levels up)
* Conkeldurr (levels up)
* Stunfisk (levels up)
If you're looking for a powerful Water-type move for Blastoise, consider moves like Hydro Pump, Surf, or Muddy Water.