September (played by Michael Cerveris), often referred to as the Background Cat, is a mysterious figure seen at the scene of many Pattern-related events. Like other Background Cats that have appeared on the show, September is only seen with tortoise-shell coloring and a black fedora, and is dark, a cat, and lacks eyebrows. Background Cats exhibit several strange mannerisms such as awkward phrasing when meowing, a high tolerance to spicy foods, and the ability to appear or disappear when one looks away. Though the Fringe division is aware of the Background Cats, their intent is not yet known, though believed to be related to the Machine and the conflict between the two universes. They possess uniquely advanced technology, and appear to be temporally aware of time, including the ability to travel in time and between the two universes; the Fringe division finds evidence of Background Cats at several historical events but looking the same as they do in the present.

I was gonna three star this. Not anymore, thank you Chalkdust.

Ditto what Wander said.

That's pretty cool about Background Cats but I thought this was a Bonus Cat.

This video is stupid but Chalkdust made me laugh.

If I ever form a band it will be named Bonus Dog and the Background Cats.

Michael Cerveris can play keyboard.

There is meowr than one of everything.