Dimensional Shambler

As their name might suggest, Dimensional Shamblers, sometime referred to as The Hunters from Beyond, are a species of alien beings who originate on a plane of distance very different from our own. They make their appearances in H.P. Lovecraft's Cthulhu Mythos.

Description
Hunched humanoid monstrosities with leathery grey skin, Shamblers possess yellow slit-like eyes and long fangs. They tend to adopt a hunched, semi-simian pose, with their overlong arms dragging along the ground; these arms are tipped with a pair of enormous and wickedly sharp claws. Although appearing to be corporeal, their dimension-hopping nature means that they possess no actual physical form on Earth, a fact which makes defeating a Shambler using conventional methods highly problematic, if not completely impossible.

Origins
Shamblers originate from a lower dimension than ours, a place described as "a long, grey, oozing plain, beneath skies where the fumes of Hell were writhing like a million ghostly and distorted dragons." How they switch between dimensions at will in the way that they do is unknown.

Behaviour
Shamblers can travel between planes of existence on a whim, but how they choose their destinations remains a mystery. However, it is known that certain arcane rituals may be used to summon one, and bind it to the summoners will. Once materialised, Shamblers will select (or be designated) a victim; they will then pursue that victim, making small teleporting dimensional "hops" to close the distance between them, all the while appearing to grasp for their prey. Although seeming to reach for their victim, they actually use a form of mental control to ensnare their target, and this may be resisted by those with a strong enough will. However, once caught in the psychic net of a Shambler, the poor unfortunate will be dragged to their alien dimension where they will sink into the slime of the surface to have their minds and souls consumed by these strange creatures.

Trivia

 * It is known that the summoning of the Outer God named Kaajh'Kaalbh requires the participation of a Dimensional Shambler, although what form this aid may take is an undivulged secret.