Auntie Viv

Auntie Viv is an elderly, yet surprisingly robust, hamster. Even though she's very old, she is incredibly skilled at athletics; she loves doing activities like snowboarding, skateboarding, and running marathons. She can sometimes act wild and be rude, especially towards Elder Ham; but in most cases she is kind, and will sometimes give the Ham-Hams free advice.

(Source: Hamtaro Wiki)