Darplan

is a Dark-type Pokemon made by Slk Mugen for Generation ST. It evolves into Planetta starting at level 27 when a Grass-type Pokemon is in your party.

Biology
Darplan are small, gentle creatures. They are very human like, and are often confused for a halloween costume.

Trivia

 * Excluding the evolution of Eevee to Leafeon, Darplan is the only Pokemon that becomes a Grass-type Pokemon that originally does not start out as one.
 * It's evolution method is exclusive to it and Pancham, however, it requires Grass-type Pokemon rather than Dark-type Pokemon.