Battery Dragon

Breeding Guide
The Battery Dragon is a Hybrid Dragon with can be obtained by breeding an Electric Dragon with a Metal Dragon at the Breeding Mountain or the Ultra Breeding Tree.

However, breeding an Electric Dragon with a Metal Dragon may also result in a Gold Dragon.

Damage Calculator
To explain: When attacking with Metal, Battery deals double damage against Earth and Ice, half damage against Fire and Metal, and no damage against Electric. When attacking Electric, Battery deals double damage against Fire and Metal, half damage against Dark, and no damage against Earth or Electric. When defending, Battery takes double damage from Water and Plant, half damage from Ice and takes no damage from Electric or Metal.

Trivia

 * During its adolescent stage, it can detaches its body parts with the battery in the center and it's detached parts spin around it.