Charjabug

Charjabug is a Bug-type/Electric-type Battery Pokémon.

It evolved form of Grubbin and evolves into Vikavolt when leveled up in a special magnetic field (in Generation VII) or when exposed to a Thunder Stone (in Generation VIII).

Biology
Charjabug is a small, cuboid Pokémon resembling an insect. Its body consists of three square segments. The last two sections have a thin, ring-like marking and a stubby brown leg on each side. Each eye is covered by a blue screen and are only visible when they glow. Two short, yellow spikes extend from the front square: one on each side of its rectangular mouth. The mouth itself is gray and has two jaws that close sideways, shaped like a lightning bolt when open.

Charjabug is often found half-buried in earth or leaves, munching on humus. In its body is an electric sac, which it uses to store electricity generated by digesting food. The electricity it stores could run a household for a whole day and can be shared with other Pokémon. As shown in the anime, it can send sound waves to communicate with nearby Grubbin.