Its body is almost entirely composed of water. It ensnares its foe with its two long tentacles, then stabs with the poison stingers at their tips.
Biology
Physiology
(From Bulbapedia ) 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 entire body is made of 99% water - the remaining 1% containing the organ that makes its poison.
Tentacool absorbs sunlight and refracts it using water inside its body to convert it into beam energy. It is also able to control Pokémon it touches with its tentacles, which can regenerate. Tentacool can be found throughout the ocean. It will sometimes wash ashore and become shriveled and dehydrated, but may be revived if it is thrown back into the ocean.
Relic Tentacool's Source of power is the orb it holds in its tentacles. It is incredibly vulnerable without the orb, so it will defend it with its life
(From Bulbapedia) Tentacool is based on a jellyfish, possibly a species of box jellyfish such as Chironex fleckeri or Carukia barnesi. The fact that it has only two tentacles may be based on squid.
Relic Tentacool is inspired by witch hats.
Name origin
(From Bulbapedia) Tentacool is a combination of tentacle and cool.