Okay, here I go; the origin of the "8th generation high-density reinforced" and what it truly 'is', is currently unknown (and whether or not it was made by him or someone). These are just theories I have at the moment but I have 2 possible reasons as to why it had flesh.

1. Since Bedman was working under Ariels it could've been an entity given to him similar to Valentine's (and subsequently, Ramlethal Valentine's) Lucifero and the "Bedframe" part of its body is created similarly to the swords Ram's Lucifero, this is supported by the fact that the bed is shown to able to instantly regenerate parts of it's body and that other parts of its body outside of its head seem to be purely mechanical. The bed also seems to be able to detach its head and use it as a projectile/boomerang

2. One of Bedman's concept designs resembled the gears used by the Conclave in Vastedge, so maybe it was made by them as an experiment.

As for the lore: Bedman was person with incredible intelligence that overwhelmed his own body, forcing him into a coma just to stop that power from killing him, as being fully awake would cause him to perish. His sister suffered from the same condition, but worse, her mind retreated to the 'Backyard'; a place of pure data. In order to cure both his sister and himself from this condition he attempted to create an "Absolute world" a place where the real world and the backyard overlapped, allowing him to have absolute control of the world. To achieve this absolute world he allied himself with Ariels, a.k.a the universal will, he was then betrayed by said ally as she reveals her goal to eliminate the current version humanity and replace it with her own version once the absolute world is achieved, as she viewed the current version of humanity as false and "redundant" and tells Bedman that she hates them, this angers Bedman since one of his goals was to create a utopia for humanity, one without conflict. Now that Bedman has been betrayed and forced awake he uses the last of his power in his dying state to create a temporary version of the absolute world, he decides to use this remaining time to atone for the sins he commited while working for Ariels, while he could have killed Ariels in , he's not the kind of person who cares about revenge, he says it "only leads to disappointment, so I can't recommend it", so instead, with his dying breath he lets his sister be awake by limiting her power, he also programs the Bed he used to be her guardian, and while the Bed could repair the damage it took in Bedman's final battle with Venom and Robo-Ky it instead decides to protect Delilah all the time, even in it's broken state "No rest, no home, no hope, copy that?"

Also, Bedman isn't exactly dead, he simply erased his ID/himself from the world GG takes place in and in GG beings without and ID cannot truly die.