Mirror Dragon

Breeding
To obtain the Mirror dragon you must breed two rare hybrids together at the Breeding Mountain or Ultra Breeding Tree

Rare Hybrids are Dragons, which you can't breed by two elemental Dragons. This means you have to breed them by Hybrid + Hybrid or Elemental + Hybrid, for example: By  breeding Soccer + Soccer or Cool Fire + Cool Fire you will have the highest chances to get a legendary Hybrid, because these combinations have a 50% chance to result in one of the 4 legendary Hybrids.
 * Gummy Dragon
 * Pirate Dragon
 * Petroleum Dragon
 * Armadillo Dragon
 * Cool Fire Dragon
 * Soccer Dragon
 * Poo Dragon
 * Fluorescnet Dragon
 * Moose Dragon
 * And many more

Damage Calculator
To explain, when attacking with Legendary, Mirror deals double damage against other Legendary Dragons, and normal damage against everything else (?). When defending, Mirror takes double damage from Legendary Attacks and half damage from Physical Attacks.