Gastly

That's Gastly over my cat, 

Wendy, cleaning herself. 

Gastly was a scary Ghost Pokémon with a Body being 95% poisonous Gas 

wide pink Mouth, and 2 sharp Fangs. 

And these glaring Eyes seems 

to extend past its round Body. 

In the Episode called "The Ghost of Maiden Peak", Gastly talked like Humans, 

and in the Episode called "The Tower of Terror" Gastly says, "Gastly". 

I suppose Gastly was based on a Word, Ghastly.