Gastly a. : See Ghastful, Ghastly.

Example:
How can I get my Gastly to relearn Hypnosis?

Taxonomy
Pokémon, gas, Pokédex, Generation, effectiveness, body, wind, Pokémon encyclopedia, strong wind, opponent, gaseous body, Game, STAB, Poison, Bulbapedia, Atk, Def, Ghost Pokémon.

Defination from the web:
Gastly's evolutionary level, it is quite powerful at using special attacks such as Shadow Ball, Dark Pulse, Thunderbolt, and Energy Ball. Gastly can learn quite a few moves with all sorts of disruptive effects such as Will-O-Wisp, Confuse Ray, Hypnosis, Taunt, and Embargo. ...