That shriek is something Peter will be hearing in his nightmares. It's earth-splitting, like someone shoved a spike through his skull and it hits all the animal oh shit instincts evolution left over. Peter starts to pull on the door only to find he can't, something's stopping it from closing all the way and that's when he looks down, heart in his throat, and sees these huge black claws curling around the edge.

He saw the way that thing copied him. It's smarter than he wants it to be and whatever he did to piss it off, he figures it's past the point of talking it down like people. What he needs is the door closed and if there was a window, he would've been crawling out of it as soon as the bolt went in.

Peter hefts the mop. Too close to use the quad blaster without blowing the door off too, which means he's got to do this old school. He jabs at the claws with the mop, trying to shove them back through the gap so he can pull the door shut.