These Dragons are related to Chinese Dragons.
Western dragons are enormous fire-breathing, carnivorous creatures with scales, talons and vast wings. Usually they choose the relative safety of captivity and do not require Tracking.
Scratch is a red dragon at the Wyoming Menagerie. Like most dragons, he can cast an illusion known as a glamour. Unlike most dragons who can cast glamours, Scratch's glamour is invisibility, due to his sister and mother supposed being executed. However, after Pelly, whom he was accused of killing, was found alive, he was allowed to go to a facility where the supposedly executed creatures lived to see his mom. It is possible he was reunited with his sister too.