Generation V
Zen Mode
Changes the Pokémon’s shape when HP is halved.
Detailed Effect
This Pokémon switches between Standard Mode and Zen Mode after each turn depending on its HP. Below 50% of its maximum HP, it switches to Zen Mode, and at 50% or above, it switches to Standard Mode. This Pokémon returns to Standard Mode upon leaving battle or losing this ability. This ability has no effect if this Pokémon is not a Darmanitan.
Pokémon With Zen Mode
4 canonical Pokémon forms can have this Ability.
Darmanitan Standard 
Darmanitan Zen 
Galarian Darmanitan Standard 
Galarian Darmanitan Zen