The Junker (called Super Ultra Great Mega Trashy Monster Junker Bot by Midbus) is a trash can-like robot that appears in Mario & Luigi: Bowser's Inside Story and its remake, Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey. It is fought as a boss in Peach's Castle Garden. The Junker, now called Junker X, can be fought again in The Gauntlet.
The Junker resembles a pink trash can. He has golden vacuums attached to his arms and golden eyes. His Junker X form makes him cyan and his vacuums pink. In both forms he has brown feet and golden eyes that peek out from under his lid. His design makes him similar to the Krubbish enemy from Mario & Luigi: Dream Team.
As Mario, Luigi, and Starlow search for a way inside Peach's Castle, they find an area of the garden filled with nothing but trash. Soon after, Midbus appears, claiming they will go no further. As Starlow dares him to fight the group, Midbus refuses, saying that the Dark Star will awaken soon. He then pulls out a remote control from his hammer-space and uses it to activate Junker, which springs to life from the garbage nearby. Midbus commands Junker to attack the Mario Bros. and Starlow, but he simply stands idle for a few seconds before stopping and closing his eyes, then dancing when Midbus tries to control him again. This enrages Midbus into smashing the remote, which causes Junker to go haywire and finally attack Mario and Luigi on his own as a satisfied Midbus leaves.
After his defeat, Junker begins to malfunction again and rampages through the trash, finding and throwing over the safe Bowser was captured in (which destroys it and frees him). He then runs offscreen through another pile of trash, destroying himself. This opens the path to a room containing a pipe connected to the Pipe Yard, allowing the brothers to re-enter Bowser's body. Junker's parts can be found in a pile here; past this room, a ! Block can be found that opens a shortcut through the garden.
Before each of Junker's turns, some Junker Cans will enter the battle behind it; Junker uses these cans in some of his attacks, and they are automatically defeated once the boss is taken out. Like most bosses in the remake, Junker gains the Fury status after losing half his HP, and begins attacking multiple times per turn.
One of Junker's attacks has him throw a bucket over either Mario's or Luigi's head (in a reference to the Super Famicom game Mario & Wario); they begin to blindly walk left and right while Junker pulls out Thwomps from his hammerspace and throws them over the impaired brother. Pressing Mario or Luigi's corresponding button while they walk causes them to jump in place, and must be used to prevent them walking under the Thwomps as they try to land on them. The attack continues until either the target brother is hit (which may render them dizzy) or Junker stops throwing Thwomps and the bucket falls off.
Junker can also walk towards Mario or Luigi and throw a ball of metal scrap at them; dodging by jumping has them land on top of the scrap ball as Junker throws a larger one at them. If this one is dodged as well, Junker prepares to ram through the scrap ball; Mario or Luigi must jump a third time to avoid being knocked off the ball of scrap and taking significant damage. If they land on his head, the Junker takes damage.
Junker sometimes picks up one of the Junker Cans and empties its contents; this includes enemies that attack Mario or Luigi. Junker looks at the target brother before shaking out each item, most of which can be dodged by jumping.
- Bob-ombs light their fuses before charging one of the Bros., dealing significant damage on contact.
- Scutlets drop out and immediately charge Mario or Luigi; they are absent in the remake.
- Cheep Cheeps bounce over their target, damaging Mario or Luigi if they jump into it. The remake replaces these with Poison Mushrooms, which can additionally poison them if hit.
- Wads of paper and briefs will also fall out, which do nothing if they make contact.
Once the Junker has emptied it, the Junker Can is removed from battle; in the original, he will simply toss it away, while in the remake the Junker throws his empty can toward Mario or Luigi. This can also be avoided by jumping.
Junker can also incapacitate Luigi by tossing him into one of the Junker Cans. In the original version, this attack cannot be avoided; in the remake, Junker will use a suction attack that Luigi can escape by pressing the B button repeatedly. If captured, Junker tosses Luigi behind him into the Junker Can; sometimes Luigi may hit the rim instead and return to his original position as he wraps around the screen. While Luigi is trapped, Mario cannot use Bros. Attacks or multi-targeting items, and if he is defeated, the can then drains Luigi's HP to 0 and KOs him as well, resulting in a Game Over. Defeating the Junker Can holding Luigi frees him; after enough turns, Luigi may escape on his own. The Junker Cans occasionally shuffle their contents between each other, and Luigi sometimes peeks out of his can and waves at Mario before he gets bitten.
On initiative count 75 (113 with the Challenge Medal, 152 in the Gauntlet, 228 in the Gauntlet with the Challenge Medal), the Junker Cans will charge. Their charge can be blocked with the hammer. This happens every turn, even if the bros. incapacitate the Junker somehow. However, the Junker Cans also have their own health, and when they are destroyed, the cans leave behind an angry Chain Chomp, Nooz, or Fishbone that charges.
The Junker himself is a level 26 monster that has 1,445 hit points, attack power 120, defense 89, and speed 72, and gives 6,000 experience points and 900 coins upon defeat. If a Mario brother has the Challenge Medal, the Junker is buffed to have 2,168 hit points, attack power 300, defense 134, and speed 108, and gives 1,350 coins.
In the Battle Ring, the stats change to:
- Stamina: 3,080 hit points (4,620 if the bros. wear the Challenge Medal)
- Attack Power: 179 (448 with the Challenge Medal)
- Defense: 129 (194 with the Challenge Medal)
- Speed: 123 (185 with the Challenge Medal).
- Junker X and Bowser X are the only bosses that aren't in Bowser's body that can be fought in The Gauntlet.
- Junker Can