Shellder is a bivalve mollusk Pokémon encased within a spiky, blue-violet bivalve shell. It has two round white eyes with tiny black pupils. Its enormously long red tongue is used to burrow itself into the sand to sleep overnight and also to lure and capture prey. The tongue protrudes even when its shell is closed and tugging it will cause the shell to pop open. Its soft and tender body is well-protected by its extremely durable shell, which is purported to be harder than diamonds and has historically been used by people to make shields. It can make pearls from accumulated sand, though it discards them as they are typically in its way.
Shellder has an unusually strong appetite for the tail of a Slowpoke and can develop a symbiotic relationship with the Dopey Pokémon. After attaching itself to the Slowpoke's tail, the two undergo a metamorphosis and evolve into Slowbro together. Alternatively, if it attaches to the head of a Slowpoke in possession of a King's Rock, the two will instead evolve into Slowking. These relationships allow it to travel onto land and begin a new stage in its life cycle. In Galar, Shellder attaches to the forearms and heads of Galarian Slowpoke wearing Galarica Cuffs or Galarica Wreaths, causing the evolution into Galarian Slowbro and Galarian Slowking, respectively.
Regardless of which form the two Pokémon evolve into, Shellder's shell transforms into a spiny, spiraled cone with several tiers. Sharp teeth develop around the rim of the shell to anchor it securely to the evolved Slowpoke, and its eyes now peek out from the bottom rim of the shell. In its crown form, Shellder will have a red jewel on its underside and a large horn on either side of its shell.
While in its crown form, Shellder will periodically release its venom into Slowking's brain. This is actually beneficial to Slowking, as it causes the Regal Pokémon's intelligence to increase. Higher quantities of venom intensify this effect, and Shellder is easily provoked into releasing more whenever Slowking yawns. However, Shellder's poison makes Slowbro more sluggish as it continues to drain nutrients from its host's body. As seen in Slowking's Crowning! and An Evolution in Taste!, the crown form of Shellder can take control of humans who wear it and speak through its hoist. The control of Shellder wears off the moment the crown is removed.
Despite its hard shell, clamping on to an opponent will reveal its vulnerable parts. Because of this, it will only clamp itself to a foe as a last resort. It swims around its seafloor home by rapidly opening and closing its shell while facing backward. Despite its appearance, Shellder is surprisingly fast. Prehistoric Shellder were apparently preyed upon by Omastar, whose powerful bites were capable of breaking through its shell. Shellder and its evolved form, Cloyster, are related to Shellos and Gastrodon. Kingler, Rufflet, and Bruxish are modern predators of Shellder.
Prior to Generation III, Clamp was its signature move. Prior to Generation V, Icicle Spear was also its signature move, but other Pokémon could still inherit it via breeding. Additionally, prior to Generation V, Shellder and its evolved form, Cloyster, were the only known Pokémon that could have Skill Link as an Ability.
Evolution
Shellder evolves into Cloyster.
(For specifics on this Pokémon's Evolution in the games, refer to Game data→Evolution data.)
Main series
- For a comprehensive list of Shellder's appearances in the animated series as part of Slowbro or Slowking, see the animation sections of Slowbro and Slowking.
Major appearances
In The Evolution Solution, Jessie caught a Shellder on Seafoam Island. Later in the episode, it bit on a Slowpoke's tail, making it evolve into a Slowbro. Because of this, it left Team Rocket.
In A Crowning Achievement, multiple Shellder evolved many Slowpoke into Slowbro and Slowking as Alice Telesu released them.
In Battling a Cute Drama!, Marilyn thought her Shellder was the cutest Pokémon she ever saw. It was about to battle Brock's Happiny, but the match was interrupted by Team Rocket.
Minor appearances
Shellder debuted as part of a Slowbro in Island of the Giant Pokémon.
The first time an unevolved Shellder was seen was in The Bridge Bike Gang. It was sick and Nurse Joy sent Ash, Misty, and Brock over to Sunnytown (where Shellder was) to deliver some medicine.
In The Misty Mermaid, multiple Shellder resided in the Cerulean Gym, under the ownership of the Sensational Sisters. One of them reappeared in Cerulean Blues and in a fantasy in Alola, Alola!.
In Pikachu's Vacation, a Shellder was at the Pokémon Theme Park.
In The Joy of Pokémon, a sick Shellder was treated by the Nurse Joy of an unnamed island.
In The Power of One, multiple Shellder sensed the disturbance caused by Lawrence III.
In Slowking's Day, a Shellder lived in the ocean surrounding Shamouti Island.
A Shellder appeared in a fantasy in The Totodile Duel.
In The Heartbreak of Brock, a Shellder lived at Temacu's father's lab.
In Mantine Overboard!, three Shellder lived in the sea near Ogi City.
In Octillery The Outcast, a Trainer's Shellder competed in the Whirl Cup. It went up against Ash's Totodile during a qualifying match and lost.
In A Parent Trapped!, a Shellder was seen underwater.
In Nice Pryce Baby, Pryce kept several Shellder at the Mahogany Gym.
In Enlighten Up!, a Shellder living in Lake Slowpoke bit a Slowpoke's tail, evolving it in the process.
In Gonna Rule The School!, the Pokémon Trainers' School lent a Shellder to one of the school's underage students for use.
In Old Rivals, New Tricks!, a Coordinator's Shellder competed in the Sandalstraw Contest.
In Going for the Gold!, multiple Shellder were in the Ambrette Aquarium.
Three Shellder appeared in Alola to New Adventure!.
A Shellder appeared in a fantasy in Yo, Ho, Ho! Go, Popplio!.
In The Sun, the Scare, the Secret Lair!, Mallow studied multiple Shellder as part of a class assignment.
In Rocking Clawmark Hill!, a Shellder washed ashore near Professor Kukui's house.
In A Shivering Shovel Search!, a Shellder passed by underwater while Pikachu and Popplio were searching for Palossand's lost shovel.
In Dewpider Ascending!, a Shellder was half-buried in the sand.
In I Choose Paradise!, three Shellder were at the Pokémon Paradise Resort, with two under the ownership of different Trainers.
A Trainer's Shellder appeared in Exhibition Unmasked!.
Four Shellder appeared in Legend? Go! Friends? Go!.
A Shellder appeared in A Test in Paradise!.
A Trainer's Shellder appeared in Caring for a Mystery!.
In Slowking's Crowning!, a Shellder was on Slowpoke Island.
In The Cuteness Quotient!, a Trainer's Shellder competing in the Friendship Festival was targeted by Team Rocket.
A Trainer's Shellder appeared in Restore and Renew!.
A Shellder appeared in The Ancient Poké Ball.
Two Shellder appeared in Roar of the Black Rayquaza.
Two Shellder appeared in Transform! Hero of the Seas, Palafin.
Pokédex entries
- For Shellder's Pokédex entries as part of Slowbro or Slowking, see the Pokédex entries sections of Slowbro and Slowking.
POKÉTOON
A Shellder appeared in PT10, under the ownership of a Swimmer.