Joltik

“Joltik that live in cities have learned a technique for sucking electricity from the outlets in houses.”

— Pokémon Black

“They attach themselves to large-bodied Pokémon and absorb static electricity, which they store in an electric pouch.”

— Pokémon White

“Since it can’t generate its own electricity, it sticks onto large-bodied Pokémon and absorbs static electricity.”

— Pokémon Black 2