Celeva (Japanese: Sereba) is a Grass Pokémon.

Designated patrollers of the time stream, Celeva's potential responsibilities are imprinted upon it since birth. However, due to the weightiness of these responsibilities, Celeva is not able to use any dimension-manipulation powers. Celevas are chosen to evolve after proving a responsible nature for their guardian duties.

Celevas tend to frequent forests, where they provide guidance and healing for Pokémon and humans who pass through them. They are playful and optimistic creatures which prefer to socialise with other Pokémon species as opposed to others of their own kind.
 

Pokédex Entry

Celevas are thought to be the ones who maintain the presence of Gracidea Flower Gardens, to preserve the existence of the Shaymin species. On warm nights, they happily orchestrate swarms of Bug type Pokémon into elaborate light shows or musical performances.
 

References

Evolution

Evolves into Celebi via initiation rite with another Celebi.

Name Origin

English - Combination of the words 'Celebi' and 'larva'
Pronounced 'selleh-vah'

Japanese - ???