Groul

Groul is the evolved form of Hauntom. It resembles a large ghost with giant fangs.

Special abilities
Groul is a rare pokemon that only appears on holidays honouring the dead. It is unknown where it goes but is believed to travel to the afterlife.

Attacks

 * Curse-Level 43
 * Thunder-Level 48
 * Crunch-Level 53
 * Flamethrower-Level 60
 * Deathly claw-Level 67
 * Perish song-Level 75
 * Reaper stare-Level 100

In the anime
Groul is seen in an episode where Ash, Brock and Hari wait to see it. Ash uses his Pikachu to battle it but isn't able to defeat it.

Pokedex
Groul, the scary pokemon. It only appears on days honouring the dead. Facts about it are almost unknown.

In the games
In Pokemon Rainbow Groul can't be caught on any day except October 31st. The only other way to get it is to evolve Hauntom.