That Worm Feeling (1) - S1.E41

Prince Eccentro's plan to take over the Fire Dragon backfires while the Mon Colle Knights try to communicate with it. Mondo summons Storm Dragon who gets the Fire Dragon to stop. The Fire Dragon has heard of how they helped the Water Angel evolve the Water Dragon and reform Gabriolis. After the Fire Dragon left, Prince Eccentro attacked with a real Sandworm from the Earth Realm (where the Fire Dragon sent him flying). Storm Dragon is unable to stop it and Fire Dragon returns to help the Mon Colle Knights stop it with a fire cyclone battle-spell. When asked about a Monster Item as part of the Mon Colle Knights' goal to unite two worlds, he takes them to the Fire Angel.