- Voice actor: Eric Stuart (both English and Japanese)
Tentacool resembles a box jellyfish. It has a light blue, clear body with two large, transparent, red crystals on each side of its body, and one small one in the middle. It has two small eyes with black pupils and no visible irises near the base of its body. It has two tentacles laced with stinging cells. The tentacles extend from beneath its round, blue lower body, which has a cape-like formation in the back. Its height is 2'11" and weight is 100.3 lbs.
Tentacool absorbs sunlight and refracts it using water inside its body to convert it into beam energy, as seen in the episode Tentacool and Tentacruel. It is also able to control Pokémon it touches with its tentacles.
This Pokémon shoots beams from its crystal-like eyes, and are often found floating in shallow waters.
Tentacool can be found throughout the ocean, usually congregating in places where warm currents and cold currents come together, and where minerals are plentiful. They are extremely common in Kanto, Johto, Hoenn and Sinnoh.
- Main article: Pokémon food
Tentacool's debut appearance was in the episode Tentacool and Tentacruel.
It also appeared in Friends to the End during Ritchie and Assunta's battle. However, it is unknown who it belonged to. In the same episode, another Tentacool under the ownership of an unknown Trainer, appeared during the closing ceremonies of the Kanto League.
A Tentacool also appeared in Celebi: Voice of the Forest.
Two Tentacool appeared in Mantine Overboard! living underwater.
Multiple Tentacool appeared in the opening of Destiny Deoxys.
A school of Tentacool appeared in a flashback in A Cacturne for the Worse. May fears them due to being surrounded by them at one point, and her mother attempted to catch her, thinking that she was a Tentacool.
A Tentacool appeared in the opening of Lucario and the Mystery of Mew.
A Tentacool appeared in Up Close and Personable!.
Multiple Tentacool appeared in Bye Bye Psyduck.
Multiple Tentacool also appeared in The Power of One.
Tentacool, Jellyfish Pokémon. 99% of its body is made up of water.