SOS Encounter: Route 4, Route 6
Walk: Route 4 (20%), Route 6 (20%)
Its base catch rate is 170 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 Dream Ball, Love Ball or Heal Ball.
Evolution: Igglybuff → Jigglypuff → Wigglytuff (Moon Stone).
Igglybuff in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)