Dark Dragon

Breeding
The dark dragon is available from level 20. It costs 500,000 gold. The dark dragon can't breed with the water dragon.

Damage Calculator
To explain, when attacking, Dark deals double damage against Water and Metal and half damage against Plant and Dark. When defending, Dark takes double damage from Earth and Plant, half damage from Electric and Dark and take no damage from Ice.

Primary Type
Dragons whose primary type (what their defense is based on) is Dark include:

This means that all of these Dragons have the same strengths, weaknesses and resistance while defending as the Dark Dragon, which are listed above.

Trivia

 * The dark dragon takes a resemblence to the Night Fury dragons from the movie How to Train Your Dragon
 * The Dark Dragon breathes off Green Flames or Gas, indicating that it has Acidic Properties.