True to its name, Lava Rock Lair consists of lava. The enemies here include Lava Bubbles, Brolders, and Goomba Towers. Near the end of the level, the player must defeat Boss Brolder in order to gain access to a teleportation box.
- Green Star 1: At the start of the level, grab the first Brolder to throw it on one of the switches. Afterward, stand on the switch to reveal a bridge leading towards the star. If doing with other players, have one player stand on one of the switches while standing on the other without using a Brolder.
- Green Star 2: Just after coming out of the clear pipe, go in the Mystery Box nearby. In it, throw two Brolders on two switches and stand on the other to get the star within ten seconds.
- Green Star 3: Near the end of the bridge leading to the boss, throw a Brolder to the left side of the bridge where the star is.
Right after the second green star, be in Cat form to climb up the left wall just before the bridge to reach a thin ledge. Once there, climb again to reach the Brolder Stamp. The stamp looks like a personified boulder.