"It lets loose positive and negative electrical charges from its two antennas to make its prey faint. This Pokémon flashes its electric lights to exchange signals with others."
Pokemon likes to take inspiration from the real world, and that sometimes leads to Pokemon having types that you'd think shouldn't happen. For example, Chinchou is a Water/Electric type. Which seems like an oxymoron, and yet, it makes perfect sense as some real-life water creatures have electric currents in them.
Chinchou's Basic Attacks are Bubble and Spark, while its Special Attacks are Thunderbolt, Bubble Beam and Water Pulse.