S1·E37 All You Need is Lava

Professor Hiragi and Prince Eccentro don't feel like they're wanted. When in the Fire Realm, Hiragi and Eccentro are chased by a Lava Lizard. Prince Eccentro uses Teddyurnaut to take over the Lava Lizard and attack the Mon Colle Knights. Mondo and Rockna summon the Emerald Dragon and defeat the Lava Lizard with an earthshake battle-spell and the Lava Lizard falls into the crack filled with water (since it was near a lake).