Darkrai is the title given to an odd humanoid Pokémon with pure Dark type attributes. It has thought to have existed for some hundred years, this time having been spent keeping careful watch over Alamos Town, Sinnoh.

At first glance, Darkrai could be mistaken for a Ghost type Pokémon - especially as a result of its hovering and phasing through solid objects. It has the ability to put humans and other Pokémon to sleep and, due to the influence of its hallucinatory energies upon the minds of its targets, it has been given the stigma of a nightmare-bringer.

 

Pokédex Entry

If it feels its territory is threatened, it will afflict the intruders with deep, nightmarish slumbers. It appears to be most active during nights of the new moon.
 

References

Evolution

Name Origin

English - Same as Japanese origin

Japanese - From 'dark' and 'kurai' (dark) or 'rai' (Hindi for king)