Sis is a mole in Spyro: Shadow Legacy who lives in Moleville along with her family. According to herself, the Professor is not the only smart one in the family, having built a Magic Detector all by herself.
When the Calamity struck and infected all worlds with the Shadow Realm, Sis had lost her detector, which she had taken apart to built version 2, and the Shadow Minions had taken it. She tasked Spyro with finding it for her. When she got it back and built it again, the readings went off the chart, and Sis thought it was broken, but Blink said it was because the purple dragon was so powerful.