TENTACOOL's body is largely composed of water. If it is removed from the sea, it dries up like parchment. If this POKéMON happens to become dehydrated, put it back into the sea.
Sapphire:
TENTACOOL absorbs sunlight and refracts it using water inside its body to convert it into beam energy. This POKéMON shoots beams from its crystal-like eyes.
Fire Red:
Its eyes are as transparent as crystals. From them, it shoots mysterious beams of light.
Leaf Green:
Drifts in shallow seas. Anglers who hook them by accident are often punished by their stingers.
Dewford Town, Abandoned Ship, Slateport City, Lilycove City, Shoal Cave, Mossdeep City, Pacifidlog Town, Seafloor Cavern, Ever Grande City
Route 4, 10, 11, 12, 13, 19, 20, 21, 24
Pallet Town, Cerulean City, Vermilion City, Lavender Town, Cinnabar Island, One Island, Kindle Road, Treasure Beach
Bond Bridge, Icefall Cave, Five Island, Five Isle Meadow, Memorial Pillar, Water Labyrinth, Resort Gorgeous, Green Path, Water Path, Trainer Tower, Tanoby Ruins
Petalburg City, Dewford Town, Abandoned Ship, Slateport City, Lilycove City, Shoal Cave, Mossdeep City, Sootopolis City, Pacifidlog Town, Seafloor Caver, Ever Grande City (Old Rod, Great Rod)