SOS Encounter: Malie Garden (1%)
Its base catch rate is 45 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 Dive Ball.
Evolution: Poliwag → Poliwhirl (Level 25) → Poliwrath (Water Stone) · Politoed.
Poliwrath in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)