Mechanical Abomination

The opposite of a Robotic Angel. Much like a Physical Heaven and Hell existing thanks to one or the other existence, robotic demons can also co-exist with angels. This is often due to the need of keeping a balance in a plot if such creations are allow. This would sense as works are show one side needs to be heroic while the other must be the villain.

They are either of human creation or hell spawn. Sub-Trope of Our Demons Are Different.

Live-Action TV

 * Adam from Buffy the Vampire Slayer is this as a result of the experimentation to combine cybernetics and the supernatural.

Video Games

 * Among the bosses in Ōkami, Yami is a known demonic cyborg.
 * Doom has several types of these, including one named simply Cyberdemon.

Western Animation

 * The Robot Devil aka Beelzebot in Futurama is a prime example, although he does has his limits, such as finding sacrificing robot child as cruel, which Bender begs to differ.