Mi-go

The Mi-go are a mix of crab, insect, and fungus. They're infamous for surgery skills, which are often put to use removing human brains and putting them in canisters.

In the RPG...

Mi-go are one of the most common Call of Cthulhu enemies. I think this is owed to them being human-ranged in stats, while still being strange and alien in appearance and behaviour. Their bodies resonate at a different frequency to earthly beings, which means they take only minimum damage from impaling weapons. For this reason, blunt weapons or explosives would work better, though an investigator would most likely be unaware that their gun was doing so little damage until it was too late.

    Mi-go have a lot of interesting abilities and technology. As far as abilities go, they can firstly hypnotize someone with their buzzing. An average human only has a 29% chance of resisting this, so is a fairly effective ability. They also have a simple telepathy, though this requires magic-points for them to use. And lastly, they have an ability whereby they can create a sheet or sphere which light cannot pass through, which also requires magic-points.

    As for technology, there is a Mist Projector, which sprays a cone of cold mist, kind of like a inverse flame-thrower. This can be used by humans after they've passed an INT roll to figure out how. There is also a biological armor they can wear which provides 8-points of protection. This can also be used by humans, though taking it off causes 1 damage to both the wearer and the armor itself—so the 2nd time it is worn, it would only provide 7-points of protection. Though not carried across to the 7e Malleus Monstrorum, Mi-go also have an Electric Gun. It not only does 1D10 damage, but immobilizes the target for as many rounds as the damage inflicted. There is also a chance the target could die from heart failure. This was done via an opposed roll of hit-points to damage done, which seems a little convoluted. For an average human, it also works out to around a 50/50 chance, which is ridiculously high. If the Keeper wanted to keep heart failure as a possible outcome, I personally think a fumbled CON roll would suffice.

In a video game...

For the same reasons they're prevalent in the RPG, I think the Mi-go would be perfect for a regular enemy in a video game too. Their bizarre surgeries and ability to mimic humans could make for some interesting plot-twists as well.

In a film...

There are two adaptations of The Whisperer in Darkness that I know of, so the Mi-go have already had their film debuts, though I wouldn't be averse to them showing up again. They're complex enough that many a story could be written around them.