Magma Armor

This Pokémon cannot be frozen. If a Pokémon is frozen and acquires this ability, it will immediately thaw out; this includes when regaining a lost ability upon leaving battle. Overworld: If any Pokémon in the party has this ability, each egg in the party has its hatch counter decreased by 2 (rather than 1) each step cycle, making eggs hatch roughly twice as quickly. This effect does not stack if multiple Pokémon have this ability or Flame Body.

The Pokémon’s hot magma coating prevents it from being frozen.