Cloyster is a dual-type Water/Ice Pokémon introduced in Generation I. It evolves from Shellder when exposed to a Water Stone. This bivalve Pokémon is encased inside a light-gray shell, surrounded by a second jagged, blue-violet outer shell casing. Cloyster's shell is incredibly durable, said to be harder than diamond and capable of withstanding bomb blasts or even missile strikes. It has one barb-like spike protruding from above its head and multiple conical horns on its outer shell. The size and sharpness of these spikes are affected by harsh tidal currents.
On its pearl-like face, Cloyster has two white eyes and a mouth. Its internal anatomy remains largely unseen, as once it has shut its shell, it is impossible to open from the outside. This impressive defense mechanism allows Cloyster to protect itself from various threats. Interestingly, Cloyster is capable of swimming in the sea by swallowing water and then jetting it out toward the rear, using the same system to shoot spikes from its shell.
Pokédex Data
- Category: Bivalve Pokémon
- Height: 4'11" (1.5 m)
- Weight: 292.1 lbs (132.5 kg)
- Abilities: Shell Armor, Skill Link, Overcoat (Hidden)
Breeding
- Gender Ratio: 50% male, 50% female
- Egg Groups: Water 3
- Hatch Time: 5,120 steps
Pokédex Entries Across Versions
- Red/Blue: "When attacked, it launches its horns in quick volleys. Its innards have never been seen."
- Gold: "Once it slams its shell shut, it is impossible to open, even by those with superior strength."
- Ruby/Sapphire: "Cloyster is capable of swimming in the sea. It does so by swallowing water, then jetting it out toward the rear. This Pokémon shoots spikes from its shell using the same system."
- Ultra Sun: "If areas of Cloyster's very hard shell get damaged, those areas swell, gradually growing into large sharp spikes."
- Sword: "Its shell is extremely hard. It cannot be shattered, even with a bomb. The shell opens only when it is attacking."
Evolutions
Shellder → Cloyster (exposed to Water Stone)
Habits
Cloyster is known to inhabit seas with harsh tidal currents, which contribute to the growth of its large, sharp spikes. It has been observed coming up on land occasionally to search for its favorite food, Slowpoke tails. Archaeologists have discovered ancient spears tipped with spikes that had fallen off Cloyster's shells, indicating a long history of interaction with human hunters.
Additions Across Generations
In Generation 3, Cloyster gained the Skill Link ability, which ensures its multi-hit moves always hit the maximum number of times. The addition of the hidden ability Overcoat in later generations provided Cloyster with protection against weather effects and powder-based moves. These changes, along with new moves like Icicle Spear and Shell Smash, have significantly improved Cloyster's battle capabilities over time.