The Stalker is a humanoid creature with the ability to change appearance. He can be anyone he desires and take the original victim he chooses shape of, and terminate them. (For that I mean, "Kill", them.)
Coop and Kat are fighting near the woods late at night when, they heard what sounds like groaning, almost a scream, coming from inside the woods. Coop and Kat went out to investigate the noise, but found nothing. So they went back out and went back inside the Burtonburger house.
Kat was inside his scratching post lair making a device to exterminate Coop, but all the electronics start to flicker. Kat goes out and tries to figure out what is making the lights flash on and off. But never found a thing. Just then, Coop and Kat bickered again, but this time, they did find something.
It was a anonymous figure crawling on all fours, looking directly at them, it had no nose, or mouth, just two, big, round eyes staring at the two. They looked at each other in curiosity. Coop went up slowly to the being, but the ominous creature vanished in front of them.
The creature Coop and Kat saw was known in Bootsville as, "the Stalker", a anonymous being unknown by professional Biologists. It maybe a Alien, or just a Cryptid, we'll never know. But legend has it, that the only way to know its prescience, is its unearthly wail.
It is really a mystery to this day, and still is. But, the Stalker has a very keen sense of hearing, for hearing its victim's heart beat.
The Stalker has a ear splitting screech that can be heard by millions. But, he also has the same exact abilities as the CreepyPasta character known, as the "Slenderman".
All humans. (Not Coop, he feels Coop's pain.)
The Stalker is more cautious when hunting for prey, its eyes can turn black and its teeth becomes sharp and jagged when primal. It will pounce on its victim and skin and eat its prey (Or simply kill them off). It is been said that it can ensnare prey with its long tongue. But for now, its origin remains, unknown priority.