The Boomerang is a weapon and a tool given to the player by the Cardinal animal orb during the Thieves' Forest level. It is hidden behind the bushes, where the defecating owl is found perching on a tree branch. Equip Cardinal and he'll pick up the Boomerang for you. The Boomerang is used mostly to break through barriers such as doors or icicles, however, it can also be used to stun enemies and deal small amounts of damage to non-flinching enemies (like bosses). If you hold down the button, the Boomerang will charge up, letting you throw it further. This weapon has unlimited uses, and if unlocked on one character, all others may use it as well. It is not vital to complete the main story.
- Stun enemies for a brief period of time (good for setting up combos).
- You can stun foes mid-air and make them float. It can be done easily by knocking the opponent in the air through Juggling, then throwing it fast. You must be quick to follow up, however, as the stun wears off somewhat quickly.
- Taking it out mid-jump let's you go slightly further then normal, albeit it grants barely any additional distance and leaves you vulnerable due to high ending lag.
- Break through doors faster than most splashes.
- Deal minuscule amounts of damage to non-flinching enemies, which can be used to grind XP, though this is a slow process.
- Retrieve items like gold, fruit, and weapons, as long as they are within range.
- If you hold down the button, the Boomerang will charge up, letting you throw it further.
- Before the title update, the Boomerang was commonly used by players to gain massive amounts of XP by fighting either Pipistrello or the Catfish. It can also be used to gain massive XP on the first Antlion in the Desert and on the Industrial Machine's electric pillars even after the title update. These do not work in the Remastered version.
- This weapon is possibly a reference to The Legend of Zelda series, for in certain games in that franchise, the Boomerang is an optional weapon that merely stuns enemies and allows Link to retrieve distant items, while in others it can have many other uses.
- The boomerang can be thrown quite far. However, this is strange, as the traditional design is much less efficient than many other designs.
- The boomerang concept is reused in The Behemoth's other game, Battleblock Theater, with similar abilities as they can both collect items, and stun enemies.