Displacer beast

Displacer beasts are large, monstrous predators native to the Feywild.

Description
Displacer beasts look like black panthers with two tentacles or tendrils sprouting from their shoulders; the tendrils end in cupped pads with spikes. In the Monster Manual they are described as having six legs, blue-black fur, and glowing red eyes, but these details haven't been used to describe the beasts on Critical Role, and one of the displacer beasts specifically sounds like it has only two sets of feet.

Displacer beasts are shown to be relatively intelligent compared to most beasts: they're capable of organizing ambushes and waiting until their hunting partners have good position to pounce.

Abilities
Able to magically displace light, these creatures can project illusory versions of themselves several feet away from their actual location. If successfully hit, their ability to manifest these illusions is temporarily disabled.

History
Vox Machina fought displacer beasts in their pre-stream adventures.

During the Harvest Close Festival in Zadash, the Stubborn Stock defeated a pair of displacer beasts in the second round of the Victory Pit tournament.

The Mighty Nein were surrounded by three displacer beasts on Rumblecusp. Before they could attack, two were-bear villagers appeared, killing one beast and frightening off the others.

Use in crafting magical items
The pelt of a displacer beast is used to make a Cloak of Displacement, which projects an illusion of the wearer, making the wearer harder to hit.

Trivia
In the Monster Manual, displacer beasts and blink dogs kill each other on sight after a history of the Seelie Court's fey hunters using blink dogs to drive displacer beasts to the edges of the Feywild and thus into the Material Plane.