Vacuum Helmet

The Headgear is a device used by Fawful in the game, Mario & Luigi: Superstar Saga and Mario & Luigi: Bowser's Inside Story. It is used to get Fawful around and attack the Mario bros. It is also noticed to have many functions and is Fawful's most used invention.

Mario & Luigi: Superstar Saga
In Mario & Luigi: Superstar Saga, Fawful uses the Headgear to suck up Princess Peach's voice before the onset of the game. He uses the Headgear's fireball ability to battle Mario and Luigi when they come to reclaim Peach's Voice; he then uses the attack to destroy Bowser's Koopa Cruiser. Later, when Cackletta is defeated by the Mario bros., Fawful sucks her soul up with the Headgear and deposits it inside Bowser's unconscious body, thus saving her from death.

During the final battle of Superstar Saga, Fawful and his Headgear are seen in one of Cackletta's attacks, but in ghost form. In the attack, the headgear will shoot fire balls at both bros. If Fawful is in front of Mario, the Headgear will first shoot at Luigi first, then Mario. On the other hand, if Fawful is in front of Luigi, the Headgear will shoot at Mario first.

Mario & Luigi: Bowser's Inside Story
In Mario & Luigi: Bowser's Inside Story the headgear is known as Vacuum Helmet instead of it's original name, however, Fawful still calls it "his Headgear". Fawful uses the helmet to suck the power out of the Dark Star and become Dark Fawful. Afterwards the helmet is fought in the battle against Dark Fawful where Bowser can inhale it and the Mario Bros. will fight it from inside him. In this game, the helmet is less important, although it is much more life-like than before. So far, the helmet's last appearance was in Bowser's Inside Story.

Functions
The Headgear has many functions, and is primarily used by Fawful to fly around or hover. The Headgear's nozzle can both shoot fiery balls of energy at Fawful's opponents and vacuum up other things, which are then stored within the Headgear.

Mario & Luigi: Bowser's Inside Story introduces more functions, including the Headgear's ability to function independently from Fawful. It is also revealed that the Headgear's nozzle can morph into a kind of basket, inside of which Mario or Luigi can be trapped and drained of their HP. While Fawful is fighting Bowser, he may use his headgear to avoid some of Bowser's attacks or he can revive some of his own HP. The headgear also morphs it's nozzle into what looks like teeth, allowing Fawful to grab onto objects and swing from them. At some point, the headgear will fly above Fawful's head on the top screen, where Bowser can use his vacuum ability to suck it up into his body, where the bros. will fight it. After taking a certain amount of damage, the headgear will explode and cease to exist, making its last appearance.

Trivia

 * It is unknown if the Headgear has a life of its own. However, during the battle against Dark Fawful, the Headgear can be seen blinking giving more evidence that it has it's own life.
 * The top of the Headgear in Mario and Luigi: Bowser's Inside Story makes it resemble R.O.B.