Like her brother, Thornfrost is a stocky and short cat, built for stamina rather than agility. Her coat is a shade darker than Asterfang's, however, and webbed with jagged black stripes - marking her as a brown tabby.
In contrast, she has a white chest and muzzle, and her eyes are green - a yellow-lichen-moss sort of green, with amber hues. Her paws are tan and lighter than the rest of her body, with black dappling where her claws are.
Thornfrost is noticeably unscarred and smells strongly of herbs.
Thornfrost is a no-nonsense medicine-cat. She is decisive, knows how to get her point across - she sees a problem and knows how to fix it.
If Thornfrost hadn't chosen to be a medicine cat, it's likely that she would have been deputy - her quick response, her level-headedness that marks her a true BrambleClan cat. She stays calm when faced with challenges and is known to be resourceful when under pressure.
However, Thornfrost finds it difficult to emphathize with others - a strange and unusual quality for a medicine cat. She doesn't understand why cats make such a big deal about little injuries, like a thorn embedded in a paw or a small scratch on someone's flank.
She tries her best, though, and this has brought her a tendency towards understanding, or at least being there when others need her.