The Hound is a large white creature, with a skull-like head. It changes throughout the comic, growing in size with every appearance. Its hind legs that dangle behind her are broken and useless, crushed by the truck that killed her. They are disproportionately small compared to the rest of her.
The Hound grows in size in relation to the entropy. In Bina's Journals, the Hound was said to be the size of a regular dog in early loops. In its first appearance in the comics, it was about the size of a large human. It has been described by multiple characters in recent events as the size of a van or a truck.
The Hound has unnatural speed, despite its hind legs being crushed and not working. It moves with its grotesquely large front legs, and can jump incredible distances with them. It has been shown to climb and pick things up in its paws with them as well.
The Hound also makes no noise, aside from that which it makes as it moves and climbs. It does not has a supernatural ability to suppress any noise it creates, it just never growls or makes its own noise.
It can also appear whenever Gregor calls her with a whistle, as long as there is some mud from the factory nearby. It was speculated by Bina that she rebuilds herself out of the mud. The Hound can apparently be trapped in the mud if Gregor is injured before she has fully appeared.