Ground Shock
Target Grounds aren't immune to Electric but resist it instead.
17 species 6 as main 11 as innate 6 battle AI weight, −2 to 10 — 6 is the untouched default
In detail
Ground Shock allows Electric moves to hit Ground-type Pokemon for 0.5x damage.
Types that carry it
17 species Electric 17 Fairy 1 Ground 1 Psychic 1 Rock 1
As a main ability
6 speciesSelectable — one of up to three, and only one is active.
As an innate
11 speciesAlways on, alongside whichever main ability is chosen.