Giga Drain inflicts damage, and up to 50% of the damage dealt to the target is restored to the user as HP. If this attack deals 1 HP of damage, 1 HP will be restored to the user. When used on a Pokémon with the Liquid Ooze Ability, the user will lose the amount of HP it would have gained instead.
If the user is holding a Big Root, the HP restored is increased by 30% (making the restored HP 65% of the damage dealt). Big Root does not increase the damage dealt.
A nutrient-draining attack. The user's HP is restored by half the damage taken by the target.