A strange occurrence is happening in the world of Pokémon GO. Several users are reporting Shellos sightings all over, but only for a small period of time.

Various users online are claiming to have found Shellos, the sea slug Pokémon from the 4th generation. These slimy little water-types have yet to make an appearance in the mobile game, making players wonder “why now?”

One unique thing about Shellos is their regional color scheme. The Pokémon will look either pink or blue, designated as East Sea and West Sea variations, accordingly.

Don’t go putting your jacket on now and running out the door to find one for yourself. All of the reported spawn locations have since reverted back to a non-Shellos state.

Niantic hasn’t formally said anything about either the Pokémon’s appearance, nor their prompt removal. For those lucky enough to have caught one: great job! For everyone else: I hope you have something worth trading.