It infected you(?)

"A dangerous Apex Predator of unknown origin, its speed and hunting abilities are unmatched. With its unique ability to turn completely invisible, it's able to sneak up on unsuspecting prey before quickly dispatching of them without a trace. By the time you hear its howl far off in the distance, it's already too late." Or at least, that's what its survivors describe it as. Pursuer is clumsy with its prey, often not making sure it's dead before eating part of it and leaving. Pursuer only eats "Fresh" meat, only taking 2—3 bites before leaving since it's "no longer fresh" after that according to it.

Pursuer is the size of the civilians, it's natural prey, it has a pale white head and a teal face and eyes, it's eyes are almost bloodshot, completely black with teal sclera, it's teeth are uncannily human like, yet they're yellowish teal, usually stained with blood. The rest of it's body is pitch black, almost cement-like, making it very resilient to non headshots.

Pursuer is still an apex predator however, it can re arrange it's skeleton to go completely invisible, when invisible, it cannot attack since it's skeleton prevents it from doing so, it can un-shroud in seconds to attack again.

Pursuer is male.

Pursuer has long claws, and a sword it found somewhere, probably from a dead civilian. It can instinctively use that sword very well.

Pursuer can't swim.

Pursuer is able to talk. It can mimic Voices to lure people in.

Pursuer is a lot less sturdy than most would assume.

Pursuer lives wherever, whenever.

Pursuer can play the harmonica. It got the instrument from a civilian it killed, thinking the sounds it made were funny.

Pursuer is almost completely asexual. Although it can probably make friends with it's own kind.

Pursuer's name IS just pursuer. Not "The pursuer", just "Pursuer".