Ability · Gen 3 · 3 Pokémon
Magma Armor
This Pokemon cannot be frozen. Gaining this Ability while frozen cures it.
Magma Armor was introduced in Generation 3. 3 Pokémon and forms can have it.
Slugma
Magcargo
CameruptMagma Armor FAQ
What does Magma Armor do?
This Pokemon cannot be frozen. Gaining this Ability while frozen cures it.
Which Pokémon have Magma Armor?
3 Pokémon and forms can have Magma Armor: Slugma, Magcargo and Camerupt.
Effect text from Pokémon Showdown (MIT); which Pokémon have it from Showdown's Pokédex, cross-checked against PokéAPI. Unofficial fan site.