The Rage Candy Bar is an item introduced in Generation II. In Pokémon HeartGold and SoulSilver Version, it is a key item.
In Generation II, V and VI, it restores a Pokémon's HP by 20.
In HeartGold and SoulSilver, it can be given to an NPC on Underground Path between Route 5 and Route 6 in exchange for TM64 Explosion.
Since Generation VII, it instead heals all status conditions, namely Poison, Burn, Paralysis, Freeze and Sleep, and Confusion when used on a Pokémon.