Lanturn debuted in The Mystery is History, under the ownership of Oliver. He often uses it to swim on water. He also used it to play with a baby Lugia nicknamed Silver, which it befriended. It has since made further appearances in A Parent Trapped! and A Promise is a Promise.
A Lanturn appeared in Just Add Water, under the ownership of Dorian. Dorian used it to battle Ash and won after defeating his Totodile.
A Lanturn appeared in Lapras of Luxury, under the ownership of Naomi. Its Supersonic waves helped her locate singing voices of a group of Lapras.
A Lanturn appeared in Pruning a Passel of Pals!, under the ownership of Kyle. It and its Trainer were participating in the Wallace Cup, and it defeated Ash's Buizel in a battle.
A Lanturn appeared in The Legend of Thunder!, where it was seen swimming in a lake.
Multiple Lanturn appeared in Enlighten Up! as residents of Lake Slowpoke.
A Lanturn appeared in Pokémon Heroes: Latios & Latias, under the ownership of a competitor in the Tour de Alto Mare.
Multiple Lanturn appeared in Destiny Deoxys.
Multiple Lanturn appeared in Pokémon Ranger and the Temple of the Sea. They were among the Pokémon present during the final showdown with The Phantom and his crew. They briefly reappeared in a montage in The Rise of Darkrai, which chronicled the preceding nine movies.
Multiple Lanturn appeared in Kalos, Where Dreams and Adventures Begin!.
A Lanturn appeared in a fantasy in Clemont's Got a Secret!.
Multiple Lanturn appeared in Going for the Gold!, where they were among the Pokémon seen in the Ambrette Aquarium.
A Lanturn appeared in Securing the Future!, where it joined the rest of Alola in showering Necrozma with light so it could return to its normal form.
A Lanturn appeared in Pikachu's Exciting Adventure!.
||Lanturn, the Light Pokémon. The light that emits from its tentacle-like limb shines bright enough to illuminate the bottom of a deep sea.
||Lanturn, the Light Pokémon, and the evolved form of Chinchou. Lanturn's antenna light is strong enough to penetrate the ocean, and can be seen on the water's surface.
Lanturn is based on an anglerfish, more specifically the footballfish, although it shares some similarities with dolphins. It is also possible that Lanturn's origin contains a small piece of Apollo, the Greek god of light whose signature animal was the dolphin.
Lanturn is a corruption of lantern. It may also be a combination of lantern and turn (as in "turn on the light").
Lantern is literally lantern.