Dark Mechawful

Dark Mechawful is an enemy in Mario & Luigi: Bowser's Inside Story that is a blue, robotic Fawful most likely invented by Fawful himself. They can be encountered in Peach's Castle. They are similar to normal Mechawfuls in appearance, but are blue instead of green, have a wheel rather than legs, and are only encountered by Bowser.

In battle, Dark Mechawfuls attack Bowser by reeling its arm back and starting a short countdown of 4 or 5 seconds. When the number hits zero, the Dark Mechawful will attempt to dash forward and punch Bowser. This can be avoided by hitting the button right before the countdown hits zero to punch the robot and counterattack it as it lunges forward to hit Bowser. It will also attack by shooting a giant, purple laser at Bowser while gradually approaching to hit him with its hands. The player must hit to make Bowser duck, avoiding the laser, and will then have to make Bowser punch the robot with  before it smashes him.

After depleting the body of its health, the head of the Dark Mechawful will fly to the top screen. Unlike Mechawfuls, the head will never be destroyed with the body altogether, no matter how much damage is incurred in a single attack. If there are no other surviving enemies in the battle, all Dark Mechawful heads will fly away and the player will win the battle. If another enemy is in battle, it will remain at the top screen where Bowser can inhale it. It is thus impossible to fully defeat every single Dark Mechawful head in a battle consisting only of Dark Mechawfuls, for at least one will always escape as soon as Bowser has nothing left to fight on the bottom screen. If Bowser does not inhale the head, it might summon another body, turning it into the Dark Mechawful.5. This body will have an iron grey cloak that makes it even more similar to the real Dark Fawful and boost its power, defense, and attack speed. Its most notable difference is that its timer will now go haywire when it hits the 2 second mark, making its attacks much more frustrating to counter and giving full incentive for Bowser to inhale the head before it gets that chance.

In Bowser's body, the head has two attacks. One attack involves the head flying over a Mario Bro. and trying to fall on top of him, exactly like what the normal Mechawfuls do; the Bros. need to counter this with their hammers. A second attack begins with the Dark Mechawful tracing the ground with a harmless red laser in varying patterns: this will soon be followed by a damaging array of stars that the Bros. must jump over. The stars follow the same pattern as the red laser, necessitating memorization of the laser's positions or good reflexes to avoid the attack.

Bowser can use the Vacuum Block to inhale a Blitty from the Dark Mechawfuls in Peach's Castle, the very last one possible to obtain.

In the original game, Mario and Luigi cannot fight Dark Mechawfuls but only their normal counterpart; however, with cheats enabled and fighting them, their punch dash attack works normally and can be counterattacked, but if they perform their purple laser attack, it puts the Dark Mechawfuls in an unstable state where the game thinks their heads are out of their body and they perform the attack that only Mario and Luigi can encounter. The red laser zigzags into different positions three times and shoots out stars very slowly one by one, then the game proceeds to be softlocked after the attack is finished.

Trivia

 * Dark Mechawfuls share many similarities to the final enemies of the game:
 * The punching attack is similar to that used by Dark Bowser.
 * The laser attack the Dark Mechawful uses on Bowser is quite similar to the lasers used by both the Dark Star and the Dark Star Core.
 * The head looks very similar to one of Fawful's forms after he is defeated by Bowser.
 * The Dark Mechawful.5 looks similar to Dark Fawful.
 * Dark Mechawfuls are one of the few enemies to not appear in Bowser Jr.'s Journey.