SCP Foundation

1. It has to be BIOLOGICAL. That is, it has to be an animal that has evolved alongside humanity to be in the shape that it is now. It is not an everyday cursed object.
2. It has to be PREDATORY. It doesn't just kill any human that touches it, it actively hunts them and eats them alive HOLY SHIT HUGE EAGLE okay I'm good.
3. It has to be CAMOFLAUGED. It is not a shapeshifter whose default form is a pool of black sludge/mass of organs/regular humanoid. It is an animal that wholesale looks like, say, a chair, or your computer.

Please put some below!~

153 - Drain Worms seems to fit the bill nicely.

SCP-1701 might fit.

Man eating, and only man. It might not be biological, but who known?

I'm fond of SCP-799.