West Sea shiny
East Sea shiny
Sea Slug Pokémon
12 - 1,136
17 - 156
Available in the
Available from the
Shellos is a Water-type region-exclusive Pokémon from the Sinnoh region. It evolves into Gastrodon after being fed 50 candies. West Sea is available in west of longitude 0 while East Sea is available in east of it.
Shellos - Sea Slug Pokémon
When it senses danger, a purple liquid oozes out of it. The liquid is thought to be something like greasy sweat.
Shellos is the part of a two-member
East Sea Shellos Pokédex entry
On April 29 th, 2019, there were various reports of both forms of Shellos appearing around the world. About ten minutes later, the spawns ceased and the Shellos were reverted back to  event spawns.
 Shellos was released on May 17.
Both forms of Shellos appeared around the world in the first half hour. Then they were taken down and became region-exclusive Pokémon few hours later.
 In the wild, maximum capture CP of Shellos is 973, however it can reach 1,054, if encountered Pokémon is boosted by current weather.
page, on the official Pokédex website
Shellos Shellos article, on the Pokémon Wiki