Mittens

Mittens is a white cat that can be seen fighting rats in the Varrock Rat Pits alongside Treacle. She appears to be a full grown cat, as the Varrock Rat Pits is only for fully-grown, but not overgrown, cats. Her green eyes bear resemblance to the cat Fluffs, the cat rescued in the Gertrude's Cat quest. This may suggest that she is Fluffs's mother, but this is unconfirmed. As she fights, she can occasionally get killed by a rat.