Thunder Dragon + Muka Muka → Stone D.

Thunder Dragon + Sand Stone → Stone D.

Thunder Dragon + Boulder Tortoise → Kairyu-shin

Thunder Dragon + Fire Kraken → Kairyu-shin

Thunder Dragon + Turtle Bird → Sea King Dragon

Thunder Dragon + Star Boy → Kairyu-shin

Thunder Dragon + Spirit of the Mountain → Kaminari Attack

Thunder Dragon + Eldeen → Kaminari Attack

Thunder Dragon + Mega Thunderball → Twin-headed Thunder Dragon

Thunder Dragon + Corroding Shark → Skelgon

Thunder Dragon + Dharma Cannon → Metal Dragon

Thunder Dragon + Skelgon → Twin-headed Thunder Dragon