Stunfisk is a flat fish-like Pokémon. Its body is mostly a muddy brown color, which allows it to camouflage as it hides beneath the water. It has two short brown fins on either side of its flat body, and a bright yellow tail fin. Two yellow markings run down its back. It has round eyes with black pupils, and pale brown lips. It smiles when it emits electricity.
Stunfisk is the first Pokémon that has a Ground/Electric-type combination.
Despite living in water and being based on a fish, Stunfisk is not a Water-type.
Before Pokémon Black and White, Stunfisk originally had Electric as a primary type, and Ground as a secondary type, but later it turns to have Ground as its primary type, and Electric as a secondary type.
Stunfisk is the one of the two Electric-type Pokémon to be weak to Water-type moves, Heat Rotom being the other.
Both of Stunfisk's abilities, Static and Limber, are related to the paralysis status condition.
In the Generation VI games, Static becomes useless, because Electric-type Pokémon can't be paralyzed anymore.
Stunfisk is the only known Pokémon to both be weak against its own type and immune to its own type, as well as being the only aquatic Pokémon to be weak to Water-type moves.
If you talk to a doctor in Humilau City, he will tell you that sleeping on a Stunfisk relaxes the body with its electricity.
Stunfisk resembles a dab or flounder with traits of an electric ray. It is possible that it is also based on the stargazer fish, which buries itself in the sea bottom and emits electricity when disturbed.
Stunfisk's name comes from the word "stun", and the word "Hundfisk" which is Swedish for "Mudminnow"