Thunder Dragon + Bolt Escargot → Twin-headed Thunder Dragon

Thunder Dragon + Bolt Penguin → Twin-headed Thunder Dragon

Thunder Dragon + The Immortal of Thunder → Twin-headed Thunder Dragon

Thunder Dragon + Electric Snake → Twin-headed Thunder Dragon

Thunder Dragon + Armed Ninja → Sword Arm of Dragon

Thunder Dragon + Magical Ghost → Skelgon

Thunder Dragon + Sea Kamen → Kairyu-shin

Thunder Dragon + Ameba → Kairyu-shin

Thunder Dragon + Boo Koo → Kaminari Attack

Thunder Dragon + Rainbow Flower → B. Dragon Jungle King

Thunder Dragon + Barrel Lily → B. Dragon Jungle King

Thunder Dragon + Maha Vailo → Kaminari Attack