Pokemon Sun & Moon guide: how to evolve every new Pokemon. Grass-type starter Pokemon Rowlet evolves into its second form at level 17. It then evolves once more into its final form Decidueye at level 34. Much like the other starters, fire-type Litten evolves into second form Torracat at level 17. It will grow into the massive-looking Incineroar at level 34. Water-type starter Popplio evolves into its second version in Brionne at level 17, and like the other starters reaches its final form, Primarina, at level 34.