Heat-Sensitive Stickers are devices used by the Bravest Warriors, as well as their parents, the Courageous Battlers. The stickers are primarily used in combat scenarios, though they can be used in other situations, as well. Upon being rubbed, the stickers summon brightly-colored holographic creatures called Holo-Pets, which can each take on different forms, though every form has an animal theme. The type of animal that is summoned depends on a user’s psyche, and no two users have summoned the same Holo-Pet. However, it has been shown that a Holo-Pet can be altered if the user’s state of mind changes. For example, the Holo-Pet of Johnny Tezuka was originally a caribou (as stated by his daughter), but it became another Aeon Worm when Johnny went insane.