Mt. Lavalava is a volcano on Lavalava island in Paper Mario. It is located on the island's east coast. There is an opening in the volcano that allows one to go inside. Mario had to go inside to rescue the Fifth Star Spirit Misstar and fight the Lava Piranha. The inside of Mt. Lavalava contains an enormous amount of magma. Each catacomb is filled with magma and stepping stones used to get past it.
As Mario traveled through the mountain Kolorado followed in order to obtain a treasure located inside. Putrid Piranhas occasionally appeared and disappeared to alert the Lava Piranha of Mario's presence. Mario was able to defeat the monster and rescue Misstar. Then she helped Mario and Kolorado escape before the volcano erupted.