Scientist: *Looking over files*
transmission: Sir, one of them got loose-
Scientist: Get him or her high on anesthetics again and-
transmission: NO! He's killed three of my men! He's gone crazy!
Scientist: What?
transmission: He's somewhere in the building, and he's killing people! We need to find him!
Scientist: Call down the- *Is grabbed from behind* HRK! KGUH!!!!
????: *Strangling and digging claws into his neck* ... ... ...
Transmission: Sir? Sir!?
????: *Chomp on his neck and tears out his spine*
Scientist: *Dies and falls out of the chair*
????: *Runs off*
transmission: Sir!? What happened? Sir! sir!...
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This is not just a one-off. It's cannon background for a character.
Do you know who? I've left a hint

Art, story, and characters © ME