Arachnotron

"Maybe cybernetics wasn't such a great idea after all. Look what the demons have done with it. It seems unfair somehow you're not the only guy in Hell with a plasma gun."

- Description in the Doom II manual

The Arachnotron is a spider-like cyborg monster introduced in Doom II. It is similar in appearance to the Spiderdemon, but smaller and with large eyes that change color depending on the monster's current state (moving, hurt, or attacking). It is supported by a metal chassis and a body that consists primarily of a large brain, along with two small arms. Instead of a chaingun, it wields a powerful plasma gun that fires bursts of yellow and green energy.