Ashen Ones

Ashen Ones are magical creations composed of the dust of ground bones.

In the RPG...

Ashen Ones are a new addition to the 7e Malleus Monstrorum, though I can't help but wonder if they are a re-working of the Dust-Men from the old edition, as they do share some similarities, such as their whirling form and possession. Unlike the Dust-Men, however, their default state is a solid, human form, whereas the Dust-Men only took a human form in the Dreamlands, remaining as whirling dust while in the Waking World. 

    Ashen Ones have roughly human stats, though their DEX is a fair bit higher. Their attacks are not particularly damaging, with a standard attack averaging 4 damage, and their whirling attack averaging 5 (though the latter has an automatic success). Due to the Ashen One's composition, impaling weapons only do minimum damage, so bullets and knives are less useful than clubs, or even fists. 

    One thing I'm surprised wasn't included in the stat block, is an ability to regenerate. I would have thought the lost dust could simply recombine like it would have to do after using its whirling ability. 

    As I mentioned above, the Ashen Ones can also possess someone. This is done by entering their mouth, nose, and ears, and winning an opposed POW roll. This works out to only about a 29% chance against an average Investigator, so is not particularly efficient. However, success grants complete control of the possessed, so you wouldn't want it to be too easy.

In a video game...

Ashen Ones are not very difficult to defeat, so would be fine in that regard, though I'm not sure how possession would work in a video game context. The game would probably need to be an open-world so that it could fade to black, with the character waking up after the Ashen One has departed, leaving them to wonder what has transpired in the meantime.

In a film...

I see no reason why an Ashen One wouldn't work in a film. I feel like it's an idea that would likely have been done before, though I'm failing to think of any examples.