SOS Encounter: Memorial Hill
Walk: Memorial Hill (30%)
NPC Trade: Tapu Village (Only in Ultra Sun & Ultra Moon)
Its base catch rate is 120 out of 255 (higher is easier); the catch rate calculator works out your odds with each ball. For the look, the best colour match is Dusk Ball, Nest Ball or Safari Ball.
Evolution: Phantump → Trevenant (Trade).
Phantump in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)