that have been genetically engineered by humans for a specific purpose: killing. B.O.W.'s are the main; several of these living weapons have been created and used by

Durability: Being constructed of concrete and rebar, SCP-173 is incredibly durable, able to hold its own in a fight against SCP-682, a massive reptilian beast with almost unlimited regenerative powers that is widely considered the most dangerous SCP the Foundation has, and actually inspire fear in the creature from that day forward.
Strength: SCP-173 is apparently strong enough to snap the neck of a fully-grown man almost instantly, although exactly how it does this is unknown.
Limited Speed: Despite the fact that it is a statue, SCP-173 can move fast enough to travel several feet in the time it takes for the human eye to reopen after blinking-it can literally move faster than the blink of an eye. However, the creature is rendered completely immobile for as long as it's in an organism's sight.