Boo Biscuit

Boo Biscuits are an item found in Mario & Luigi: Dream Team, Mario & Luigi: Paper Jam, Mario & Luigi: Superstar Saga + Bowser's Minions, and Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey. It is a Boo-shaped cookie item, that will turn Mario, Luigi, Bowser, and Paper Mario invisible when used in battle, rendering them invincible for a short time, similarly to the Repel Gel and Boo's Sheet items from the first two Paper Mario games. The user will not be able to attack until the effect wears off, however, and counterattacks will not inflict any damage on enemies at all. This item is useful if the player wants to practice countering enemy attacks, or to complete dodge-focused Expert Challenges. In shops, the Boo Biscuit costs 5 coins.

If a Sandoon swallows a brother while a Boo Biscuit is active, it will automatically deactivate, regardless of the remaining turns, and the eaten brother will be liable to taking damage while in the Sandoon. Further, if an enemy runs from battle while a Boo Biscuit is active, it will automatically deactivate and the battle will end, regardless of turns remaining.

In Mario & Luigi: Paper Jam, using Boo Biscuits in the battle with Nabbit will cause them to immediately wear off and Nabbit to run away. Boo Biscuits are also disallowed in the battle against King Bob-omb, due to it having a timer.

Names in other languages
Biscotto Boo