Camerupt

“CAMERUPT has a volcano inside its body. Magma of 18,000 degrees F courses through its body. Occasionally, the humps on this POKéMON’s back erupt, spewing the superheated magma.”

— Pokémon Ruby

“The humps on CAMERUPT’s back are formed by a transformation of its bones. They sometimes blast out molten magma. This POKéMON apparently erupts often when it is enraged.”

— Pokémon Sapphire

“A POKéMON that lives in the crater of a volcano. Every 10 years, the volcanoes on its back erupt violently. Research is under way on the cause of eruption.”

— Pokémon Emerald