Rillaboom is a Grass-type Pokémon introduced in Generation VIII. It evolves from Thwackey starting at level 35. It is the final form of Grookey. Rillaboom has a Gigantamax form that will appear in The Isle of Armor. Take a look below for 30 awesome and fun facts about Rillaboom. 1. Rillaboom is a bipedal, ape…