I was piloting a GA aircraft to Avalon (Santa Catalina Island) with a fuel stop in Torrance, California last year. After refueling in the early morning, there wasn't any traffic so we pretty much were cleared for take off way before reaching the hold-short line. However, just prior to the hold-short line, I hit the brakes because a fox (I'm pretty sure it was a fox or coyote. It definitely wasn't a bobcat or a mountain lion.) decided to stroll onto the runway and sit itself down, smack dab on the numbers... proceeding to stratch itself, haha! I called tower and said.... errrr, negative... there's an animal scratching itself on the numbers, cancel take-off, over... The guy in the tower was laughing pretty hard and asked me to report back when the animal is clear of the runway.