FlareGunCalamity

I have a cool idea for a monster that I know I'm not going to submit, but you guys are all pretty good at nitpicking and improving lore, so I thought I could write it down and get some feedback?

They're humanoid monsters inspired by classic vampires, sirens, and other such. When normal, they look like humans but with pale, paper colored skin, and their sclera and hands are black. They also have black blood which I guess would be acidic and give a persona a chemical burn. Their special ability is that they can summon arms from their back that don't harm them if they get cut off or attacked and can stretch for long distances (UNCANNEY VALLEY), but they get exhausted quickly while doing so and will pass out if they summon too many. Thoughts??