Boris the reanimated corpse (Frankenstein Style) is a huge pushover, but also somewhat of a father figure. He allows the company he works for to trample all over him, no sweat. At the same time, he takes care of his coworkers, as much as he can. He ensures everybody is fed, that they’re doing the best to complete their tasks so they don’t get reprimanded or punished. Being the most human of the monsters, it’s clear that he could run off whenever he wanted. He stays for a variety of reasons, but mostly so that he can keep an eye on the others. 

Boris' character arc shall be finally gaining a spine and doing what the other monsters need from him the most, fighting back. It’s the one thing that he’s always held back on. 

Boris’ voice is low and kindly yet a little bit scratchy and weezy, like someone who has smoked the majority of their life. His vocal cords are quite literally stitched together. Don’t lean so hard into it that it’s annoying and hurts your own throat. Just give him a deep voice, with a bit of a sickly edge.