Thunder Dragon + Griggle → B. Dragon Jungle King

Thunder Dragon + Bone Mouse → Skelgon

Thunder Dragon + Frog The Jam → Kairyu-shin

Thunder Dragon + Behegon → Kairyu-shin

Thunder Dragon + Mushroom Man #2 → Sword Arm of Dragon

Thunder Dragon + Lava Battleguard → Sword Arm of Dragon

Thunder Dragon + Tyhone #2 → Twin-headed Thunder Dragon

Thunder Dragon + The Wandering Doomed → Skelgon

Thunder Dragon + Steel Ogre Grotto #1 → Metal Dragon

Thunder Dragon + Pot the Trick → Stone D.

Thunder Dragon + Oscillo Hero → Sword Arm of Dragon

Thunder Dragon + Lesser Dragon → Twin-headed Thunder Dragon