It is not known to evolve into or from any other Pokémon.
Pincurchin is a marine, sea urchin-like Pokémon with a black body. Its face has two yellow eyes with black, triangle-shaped pupils on each and two yellow, circular mouthparts. A line of sharp spines runs down its back, along with two other lines of two spines each on the side of its body. Each spine has a grayish tip.
Pincurchin stores electricity in each spine, which flows from the tip of each one. If one gets broken off, it will still continue to emit electricity for approximately three hours. It feeds on seaweed, using its teeth to scrape it off rocks.
Pincurchin appears to be based on a sea urchin, specially the burrowing urchin. Its behavior may reference the ability that some urchins have to regenerate spines that are broken in order to inject venom as a defense mechanism, but in Pincurchin's case, it is electricity instead. It may also draw some inspiration from pincushions.
Pincurchin may be a combination of pin and sea urchin. It may be a play on pincushion.
Bachinuni may be a combination of バチン bachin (onomatopoeia for crackling electricity) and 海胆 uni (sea urchin).