Spelunkk is the third planet in Spore Hero Arena. The champion is Rocky. To get to the arena, you must go to the creature who will tell you to destroy all the inferno critter's nests. Destroy them and he will tell you to hit the rocks at the lake in this order: 2, 4, 3, 1. Do that and the path to the arena will rise. Go across the path to challenge Rocky. (You must have all 4 blue fragments).