Crypteon by @Eternity9

Type: Ground / Ghost

Ability: Mummy

Hidden Ability: Dry Skin

Classification: Mummified Fakémon

Dex Entry:

           Crypteon said to be previously owned by ancient kings and nobles, they were renown for their loyalty even after death, most willing to be buried along side their fallen owner. Though how to obtain a Crypteon is unknown as it was a well kept secret among the Royals that disappeared along with their ancient society they came from. 

Game mechanic wise:

I will just accept at this point, that I image all these fakemons to be some kind of special event, so for this 'event' the player character has been asked to assist the Professor of the region who has recently been invited to check out and archaeological dig, because they have recently discovered some unknown Pokemon fossils and wanted them to check it out.

While the player character is there, a sudden earthquake happens and the player character is dropped underground, finding themselves in a undiscovered tomb, fortunately you can still use their electronic devices and get in contact with the Pokemon Professor. So the Player character with some guidance from the Professor, travels though the underground tomb, fighting ghost and ground type Pokemon, while also translating ancient text that they find in different rooms along with disabling or bypassing some...until a miss-translation by the Professor, sends you the wrong way and now the Player character has ended up in the Royal Chamber where they encounter an ancient Cofagrigus (Totem Pokemon) and a battle takes place very quickly, afterwards the ancient Cofagrigus drops "Mysterious Artifact", that the player character can give to Eevee and it will evolve into Crypteon.