Servitors of the Outer Gods

Vaguely resembling frogs, as well as squids or octopi, these amorphous beings progress by rolling, slithering, or lurching.

In the RPG...

First of all, the image above—though how they are typically depicted—is way off scale-wise. An average Servitor is only 100 SIZ, which makes them the size of the largest human. Anyway, as their name implies, they serve the Outer Gods. These are the deities such as Azathoth, Daoloth, Nyarlathotep, Shub-Niggurath, Tulzsha, Ubbo-Sathla, Yibb-Tstll, and Yog-Sothoth, though they are most often associated just with Azathoth. 

    Servitors can summon practically any god or monster using their "flute", so are often utilised by cultists to do so. The discordant music they play adversely affects humans, so any present must make a Sanity roll every two rounds, else lose Sanity points. 

    Though not mentioned in the 7e Malleus Monstrorum, the old edition states that a human with an Art (wind instrument) skill higher than 75% can actually use the flute. A second roll at 10% can call a random monster, and a third at 10% will bind it (if called but not bound, the creature will attack everyone present). I think, in 7e, these would just become Extreme rolls. 

    Servitors are one of those creatures that physical weapons cannot harm... at all. They also regenerate 3 hit-points per round. They can attack with 1-3 tentacles at a time—dealing an average of 7 damage—four times per round, so are quite deadly, as well as being quite hard to kill.

    CON and DEX have both had their ranges increased in the 7e Malleus Monstrorum, while INT's has been decreased. All the averages remain the same, however.

In a video game...

Because of their connection to the Outer Gods, I would likely include them, but not as fightable enemies. I would, however, love for one of their flutes to be discovered and see if an appropriately-skilled player would try to use it. Either that, or have a musician NPC do so.

In a film...

Servitors could be pretty interesting in a film, especially if used as the heralds of the Outer Gods. Perhaps they show up on Earth and everyone is freaking out, but they don't attack—just play horrific music. Just as the worlds Governments are figuring out what to do about them, a much bigger threat arrives.