Displacer beast

"This creature looks like an emaciated panther, with blue-black fur, six legs, and a body that is nothing but muscle and bone. A pair of tenticles sprout from its shoulders and end in horny-ridged pads."

A displacer beast, also known as a dirlagraun, is a monstrous magical creature.

History
The beast appears to have originated in the Feywild.

Physical description
Displacer beasts are large cat-like creatures with six legs and a pair of long tentacles sprouting from their shoulders. They are covered in a pelt of blue-black fur. They are usually about 9 feet long and weigh as much as 500 pounds, but the occasional mutant can be twice this size.

Abilities
Displacer beasts use their innate magic to bend light, making them appear to be a foot or two from their actual positions.

Ecology
These monsters live in small groups or prefer to be alone. Many humanoids train them to act as guards or pets, such as evil fey and onis.

Society
Like many big cats, hunt alone, although they are sometimes encountered alone.

Discrepancy
On page 66 of the Monster Manual 3.5, the alignment of the beast is lawful evil, but in the Monster Manual 4th edition, the creatures' alignment has changed to unaligned.