Retaliation
Retaliation refers to the counterattack of stack that has been attacked. Typically creature stacks retaliate once, but griffins have two retaliations and royal griffins have unlimited number of retaliations. Also with the counterstrike spell hero can gain additional retaliations for stacks. Additionally, some creatures have special ability that allows no enemy retaliation.
More retaliations
Griffins (twice)
Royal Griffins (unlimited)
No enemy retaliation
Sprite
Harpy Hag
Hydra
Chaos Hydra
Naga
Naga Queen
Vampire
Vampire Lord
Cerberus
Devil
Arch Devil
Magic Elemental
Psychic Elemental