- "Now it is time! Now we will fight! Then you will lose! And you will cry!"
- ― Midbus
Midbus is Fawful's minion and right-hand man, and the secondary antagonist in Mario & Luigi: Bowser's Inside Story. He is a strong, pig-like creature or mutant pig, who carries Bowser to a cave in Cavi Cape when Bowser falls unconscious after inhaling the inhabitants of Peach's Castle. When Bowser gets out of the cave, Midbus fights him. Midbus wins the battle and goes to Bowser's Castle. Later in the game, Midbus is fought in Bowser's castle where he flees during that battle. The final battle against him involves him being upgraded into Blizzard Midbus a frozen version of himself. Seeing that he has some characteristics of Bowser, he can be seen as a rival for Bowser. He is pink and fat with a pig- like round nose and is a very hard enemy to beat. All in all Bowser battles Midbus three times during the game.
- Roll Attack: Midbus curls into a ball and rolls at Bowser. Bowser has to punch Midbus in order to stop the attack.
- Swelled-Up Punch: Midbus fills himself with air and tries to strike Bowser with a powerful uppercut. Bowser has to hit Midbus with multiple punches in order to stop. Midbus also will jump a little closer to battle letting himself opened for attack.
- Belly-Flop Stomp: Midbus starts jump belly-flopping multiple times and reaches high enough to attack Bowser. Bowser must pay attention to where Midbus will land.He can land on Bowser,whose he must curl into his shell in order to dodge the attack,or, Midbus can land in front of him creating a shock wave. Bowser must punch Midbus before he lands.
- Iron Ball Swing: Midbus goes to the back and comes again spinning an iron ball. Bowser must once again pay attention to where Midbus throws the Ball. If thrown low, Bowser has to punch. If thrown high, Bowser has to hide in his shell to dodge.
- Snowball Throw: Midbus jumps and hangs on the walls and starts throwing snowballs that can make Bowser sick. When Midbus is looking at Bowser, he throws the snowball at Bowser, when looking elsewhere, he throws it somewhere else. Bowser has to hide in his shell in order to dodge the attack. If Bowser dodges at least 3 snowballs, Midbus will land and make a sliding punch. Bowser has to punch Midbus in order to not get attacked.
- Freeze Slam: When Midbus is healed by his Snawfuls he will curl into a ball and hit the left wall and start scaling the right wall. Bowser must pay attention to where Midbus might hit on Bowser or in front of him however this attack is very tricky to defend because the Snawfuls also throw ice balls in order to confuse Bowser and let him open to Midbus' attack.
- Bob-Omb Snowball: Midbus will go off-screen and return walking on a giant snowball to run at Bowser, however this attack can be dodged by punching the Bob-Omb on the snowball. However, sometimes he will bring the Bob-omb to the top and hide it. In order to dodge this, you have to remember where the Bob-omb is and then punch it.
- The sign on Midbus's arm bears a resemblance to the logo seen on Pigmask machinery in MOTHER 3. Coincidentally, both BIS and MOTHER 3 were composed by Yoko Shinomura and published by Nintendo (although made by Ape).
- Additionally, Midbus himself resembles the Hog's Breath mascot (minus the sunglasses).
- Midbus' name is a pun on the phrase "mid boss".
- Midbus can be seen as a contrast to his boss Fawful, although he is far less intelligent, he is far more muscular than him.
- Midbus is the only RPG secondary antagonist who didn't battle Mario and Luigi at some point in the series.
- However, he does meet Mario and Luigi once in the game. But instead, he uses the Junker to deal with them.
- Just as Bowser seems to be a cross between a dragon and a turtle, Midbus appears to be a hybrid of a warthog and an armadillo.
- Midbus seems to be the opposite of Bowser, seeing as Bowser uses fire powers and Midbus uses ice powers.
- Midbus's signature "MUH MUH MUH!" is German for "Moo Moo Moo", which is odd, as Midbus is believed by many to be a pig of sorts.
- Midbus is the only boss that Bowser fights which the Mario Bros. cannot contribute to defeating.
- Midbus may be loosely based on Ganon from The Legend of Zelda series.
- It's unknown what happened to Midbus after the events of the game, but Midbus supposedly got free from his ice block due to Dark Bowser's storm before Bowser fights with him.