Permafrost sets an entry hazard around the target Pokémon, which will Freeze them upon switching in. It can stack up to 5 times, with each layer adding a 10% chance of incoming Pokemon being frozen upon switching in. This chance is doubled under Hail.
Permafrost has no effect against Flying-type, Ice-type, or Fire-type Pokémon or Pokémon with the Ability Levitate or Leaf Guard (during intense sunlight). However, a Flying or Levitating Pokémon will be affected if it is switched in while holding an Iron Ball, while Gravity is in effect or if Baton Passed an Ingrain. If an Ice-type or Fire-type Pokémon that is not also a Flying-type or has the Ability Levitate is switched in, it will absorb Permafrost and the effect of Permafrost will end. Also, if an Ice-type or Fire-type Pokémon that is also a Flying-type or has the Ability Levitate is switched in holding the item Iron Ball or while Gravity is in effect, it will absorb Permafrost.
If a Pokémon is holding an Air Balloon, it will not be affected by Permafrost, unless Gravity is in effect. An Ice-type or Fire-type Pokémon holding an Air Balloon will not absorb Permafrost, unless Gravity is in effect.
In the event that both Permafrost and Toxic Spikes are set on the field and the Pokémon switched in is capable of being affected by both, the Pokémon will first be poisoned before having the status immediately overwritten to frozen, regardless of the order in which the two entry hazards are placed on the field.
By leveling up
|Bold indicates a Pokémon gains STAB from this move.|
Italics indicates a Pokémon whose evolution or alternate form receives STAB from this move.
Note that this still in the process of updating. Many Pokémon who can now Permafrost are not on here.