Volt Absorb

Introduced in Generation III

Whenever an Electric-type move hits this Pokémon, it heals for 1/4 of its maximum HP, negating any other effect on it. This ability will not take effect if this Pokémon is Ground-type and thus immune to Electric moves. Electric moves will ignore this Pokémon's Substitute. This effect includes non-damaging moves, i.e. Thunder Wave.

“If hit by an Electric-type move, the Pokémon has its HP restored instead of taking damage.”