How many moles of gas are in a Pokémon Gastly?

Gastly

This year, Pokémon Go is celebrating the Halloween season with extra spooky Pokémon! As an avid fan of Pokémon as well as a chemist, I wondered, “Is there a connection between ghost Pokémon and chemistry?” With a little inspiration from last week's Mole Day, I was able to find one. (Mole Day is October 23 …