Hound of Tindalos

The Hound of Tindalos is an extra-dimensional, predatory creature from the universe of the Cthulhu mythos.

Appearance
Very little is really known of their appearance, as there're very few who do manage to survive any encounters with them. What little is described however is a quadrupedal creature with a hollow proboscis to feed on victims. They are also associated with a blue pus-like substance, along with a kind of smoke whenever they appear.

Behavior
Unlike Humans and other animals of Earth, the Hounds of Tindalos are said to live with the angles of time, whereas humans live within the curves of time. This is more proven as the Hounds of Tindalos always enter into another universe through the form of sharp corners, especially corners sharper than 120 degrees.

This ability however has its limits: a Tindalos cannot enter any area or realm that doesn't have corners to venture through.