Pff, I'll spare you the stat blocks as they're unnecessary, but this seems relevant. And very [Drafty]. Brr.
AkarsasIya, the Demon Fists of Hell
Split from the Thousand-Handed [rest of the 2cd's title], these demons had an interesting history within the Demon City. Desiring loyalty and security, [demon] believed the most obvious solution was to only trust his own hands, bound at the flesh to his servants and serfs.
Initially only intended for simple, rote tasks, Akarsaslya were often used as living aides for any number of convenient jobs- holding fast to walls and bearing torches, opening doors or acting as hangers for coats and all kinds of demon hides. Later on, [2cd] took to grafting these demon arms onto the maimed stumps of his underlings, who lost their limbs in his service. If that service was to be maimed in preparation for loyal grafting, well, few voiced their complaints and lived to repeat them.
But like with many creations of the Demon Princes of Hell, the Akarsaslya spread throughout the layers of Malfeas. Grafts were stolen from bloody stumps, and the living limbs were experimented on, twisted by fleshweaving surgeons and dosed with Malfean combat drugs. Gradually the Demon Fists of Hell separated fully from their progenitor, breeding in the vast warrens of Malfeas's layers.
Now, two dominant strains of these First Circle Demons exist with countless variants- the original pure strain, still loyal to [2cd], and the more popular and widespread 'black market' versions. The former are in normal proportion to a human's forearm, with burnished Malfean brass skin and a pair of thin muscular tendrils extending out from their elbow base.
The more common combat species are hypertrophied and often feral, breeding in the warrens and foundations of apartment buildings and sewers. Implanted with organs grown from special lichens and Kimberian corals that producer constant supplies of painkillers and combat drugs. Finally, metal is bolted on and fleshwoven into their skins, while the tendrils bulge with alien strength.
Both versions share the same natural scuttling motion, walking with their fingers and thumbs. On the backs of their hand is a single ruby red eye.
In the wild, Akarsaslya will tend to attach themselves to any other suitable demon- missing a limb or not. Doing so inflicts 1 Lethal Health Level of damage that won't heal until the Akarsaslya is removed. Depending on the demon's temperament, the fist may decide to bludgeon it's new host into unconsciousness and drag it away as a lasting food source.