It evolves from Drowzee at level 26. Drowzee can be caught on Route 215.
Hypno doesn't evolve.
You'll need to evolve Drowzee to get Hypno.
Hypno
Hypno is #97 in the national pokedex, and it is a Psychic type Pokemon.
Hypno
hypno
In Pokémon Pearl you cannot find a wild Hypno however you can find wild Drowzee as a swarming Pokémon in Route 215 and then you can evolve Drowzee starting at Level 26 additionally you can trade with another trainer for Drowzee or Hypno or you can migrate Drowzee or Hypno from a previous game such as Pokémon FireRed or Pokémon LeafGreen or you can trade with another game such as Pokémon Diamond, Pokémon HeartGold or Pokémon SoulSilver.
Catch a drowzee in a swarm and evolve it
you git it to level 26 and it evolves in to hypno.
Drowzee evolves into Hypno at level 26.
Drowzee evolves into Hypno starting at Lv26.
Drowzee and Hypno are top choices. but most psychic Pokemon know/can learn Hypnosis.