I envision them as some kind of cybernetic creation made by some mechanical components used as organs and a modified brain/control centre within a fleshy body made from a mix of genetic material originally sourced from various specimens the imperium had encountered then mixed and grown in vats.
Rules wise I am going to be using them in Necromunda as Scavvies. The rule about being able to eat a gang member to avoid starvation representing the fact that they are currently being manufactured using cheaper/less quality underhive components that break often, so if the creds can't be spent to get repairs for each unit, a unit can be sacrificed to share it's parts... also cost to recruit is more cost to build etc.
still not sure if I'm going to be converting the slaver into a scaly type or the troll slugdrool from skull pass? also really need to get some squigs to use as plague zombies/chompers...
Anyway... two down, lots to go!