On the Furries and the Furry Fandom topic on Scratch, it is said that a furry could be considered as a person who likes anthropomorphic animals.

The Scratch Cat, one of the mascots of Scratch, is an anthropomorphic cat, as seen by the feet at the lower limbs of the cat, and the fact that Scratch Cat is bipedal rather than quadrupedal.

Therefore, anyone that followed ScratchCat on Scratch is technically a furry.