|"...My mother is named Crystal, and my littermates are Ferris and Whiskers, but I don't know where they live now."|
|— Jake to Pinestar about his family in Pinestar's Choice, chapter 5|
Whiskers is a kittypet born to Crystal alongside his littermates Jake and Ferris. In Pinestar's Choice, ThunderClan raids the Twolegplace to scare off kittypets who have been crossing their borders. Though unnamed, their mother Crystal pulls them closer as screeches fill the air. Pinepaw recognizes the she-cat and lets her go as she hurriedly ushers her kits away under the guise of bedtime. She teasingly asks if he's going to give chase, but he silently promises not to bring his Clanmates to them. The kits peer around their mother, but soon disappear around a corner. Many moons later, Jake mentions to Pinestar that his siblings are Whiskers and Ferris.