Kaho's Cat Form in action.
The Cat Form is a form/ability granted in Momodora: Reverie Under the Moonlight by defeating Lubella in Whiteleaf Memorial Park. It serves as an inescapable curse at first, but after obtaining the Cat Sphere, Kaho can switch between her Human Form and her Cat Form at will, so long as the item is equipped.
While in Cat Form, all active items, except the Cat Sphere, are unusable. Additionally, while in Cat Form you cannot use your bow. Being in cat form provides you with a considerable boost to your agility, seeing a horizontal movement speed bonus of ~25% (needs confirmation) as well as a small boost to jump height. Despite appearances, cat form is not useless in combat and in some cases is more effective than the standard human form. Cat form also has a smaller hitbox, so some projectiles fired by enemies are much easier to dodge or may even fly right over your head. Melee combat using the Maple Leaf can be easier in Cat Form due to the increase in maneuverability, though keep in mind that you are unable to use any active items or your bow. While you can’t activate active items in Cat Form, buffing items such as Crystal Seed can be activated prior to transformation and they will still retain their effects when you are in Cat Form.