Animal Superheroes - A good portion of the main cast have superhero identities. Donald Duck has Papernik/Super Duck/The Duck Avenger. Goofy has Super Goof. Even Mickey gained superpowers and dressed up as a superhero, although in his case the superhero antics caused quite a bit of trouble.
Applied Phlebotinum - Romano Scarpa mastered this trope. One of the wackiest examples is a supercriminal with a flying saucer... that has a magnet that attracts tomatoes... which he refines into an extremely potent explosive substance. Don't try to think about it too much.
A-Team Firing - These being Disney comics for kids, you can't really expect anyone to get hit. Actually a common tactic Mickey uses is to bring nothing to a gunfight, disarm the crook by some improvised means and then arrest him using his own gun.
The Phantom Blot in Mickey Outwits The Phantom Blot, but it's actually justified. Near the end of the story, he reveals that he's too soft-hearted to actually watch someone die, so to make up for it, he'd composed elaborate Death Traps to try and kill Mickey off instead.
Bound and Gagged - Whenever someone gets kidnapped somehow. It also tends to happen whenever Mickey gets played for a Distressed Dude. Which means that it happens quite often.
Bungled Suicide Mickey himself - seriously! In one of the earlier daily strips of the comics back when it was first starting, Mickey got into a depressive spell because he thought Minnie loved someone else instead of him. And for several weeks worth of comic strips, he tried and failed to kill himself. Over and over and over again. Then he finally decided that life was worth living and stopped trying. See Cracked's 6 Insane Disney Comics You Won't Believe Are Real.
Captured by Cannibals - More so in the older stories, before that kind of thing became politically offensive.
Continuity Creep - Mickey's comics started out as daily gag strips for a newspaper, but as he began to have longer-running adventures, the following stories often referred to previous stories when using a recurring villain or character.
Curse of The Ancients - Everyone was using these way before the Comics Code even existed, so it's never really caused much awkwardness in the way that Gosh Dang It to Heck! tends to. Besides, can you honestly picture Mickey Mouse or any typical classic cartoon character using normal swear words while remaining in character?
Dude, Where's My Respect? - Mickey has solved numerous baffling mysteries, rescued many victims of kidnapping, caught countless crooks multiple times, returned stolen goods worth millions to their rightful owners, worked for the government, and even caught malicious spies from other countries. And yet no one thinks he's ever done anything special at all, and the stories themselves go to great lengths to point out how little he's thought of. He hardly gets any respect; given all he's accomplished, you'd expect him to be at least a little famous, but it's pretty rare for anyone to actually recognize what he's done. Mickey's too nice to really be concerned about it, but to readers it can be incredibly frustrating.
Some of the Italian strips indicate that he is at least somewhat famous, and actually has a movie made of his exploits, but prefers to remain as anonymous as possible.
Enemy Mine - It's almost to the point of Friendly Enemies or Rivalry when this happens with Pete. Almost.
Firing in the Air a Lot - In the Western-themed Sheriff of Nugget Gulch (1937), Goofy does this on the back of a train and gets him and Mickey stuck in the jailcar for the rest of the trip. They get taken to the sheriff's office at the next stop, and Mickey manages to persuade him that they aren't actually outlaws and that it was just a mistake. They walk out the door, and out of excitement, Goofy shoots around in the air again. Hilarity Ensues.
In the early Floyd Gottfredson strips, most of the characters, including Mickey, talked with a Funetik Aksent. This was toned down after a while, and Goofy became one of very few character who didn't completely lose his accent.
Gossip Evolution - A key point in Sheriff of Nugget Gulch, where Goofy's ridiculous misuse of Firing in the Air a Lot on the back of a train gets him and Mickey a reputation as dangerous & gutsy Outlaws in the next town before they even arrive, complete with their own gritty bandit names.
Got Volunteered - In Mickey Joins The Foreign Legion. He gets "volunteered" because someone jabbed him from behind with their spear. Causing him to yelp out in pain, which was of course taken as an act of volunteering.
Great Detective - Sometimes Mickey's hobby of solving crimes is raised to this level of skill (and sometimes also made his profession), particularly when he goes up against a similarly elevated Phantom Blot. A couple of stories also point out that he'd be a great criminal if he wanted to due to that same ingenuity.
Identical Stranger - It's almost ridiculous how many times Mickey's discovered that someone looks exactly like him or similar enough that they could be mistaken for each other with a few adjustments or disguises.
The Monarch of Medioka (1938): This is used for Prince and Pauper switch.
Pete himself had one of these in one story, in the form of the benevolent ruler of a small foreign country. Naturally, he took advantage of this to try and seize control of said country by swapping roles.
Inspector Javert - Mickey tends to act like this towards Pete, never believing he's mended his ways and sometimes suspecting him on principle. He's nearly always right, but it's still more prejudice than intuition.
Mirror Universe - In one series of comics, it's especially disconcerting in that the Phantom Blot, a Manipulative Bastard and trademark villain, is a superhero.
Hitler Ate Sugar - Peg-Leg Pete, being the established villain by that time, was naturally portrayed in at least one story to have been an undercover high-ranking Nazi spy all along, giving off the message of "He's evil, so he must be a Nazi!"
New Job Episode - In The Bellhop Detective (1940), Minnie forces Mickey to enter a contest where the winners get job positions. He receives a job as a bellhop, but inevitably ends up spending more time trying to solve a mystery at the hotel than actually learning to do his job right.
No Export for You - There are hundreds to thousands of the comics created internationally that haven't been officially translated to English.
Operation Jealousy - Minnie starts this a lot, usually as an attempt to get Mickey to pay more attention to her instead of going off on adventures. In one story, Mickey manages pulled a Counter Zany on her before things get sorted out.
Print Long Runners - Since 1939, folks! Early 1930's if you count when it was a newspaper strip and not in comic book format. Off and on at times, admittedly, but hey... it's still around!
Ridiculously Average Guy - A recurring joke throughout the comics; Mickey is often selected for special opportunities because he's so average - in the eyes of everyone but his friends and the reader, of course.
In Mickey Mouse and the Orbiting Nightmare (2010):
Reporter: We chose him because a group made up of such staggeringly famous people also needs an utterly ordinary everyman!
Species Surname - Mickey, Minnie, and Mortimer Mouse (none of whom are related to each other), Clarabelle Cow, Horace Horsecollar...
Stay in the Kitchen - In earlier stories, when this kind of thing wasn't really frowned upon, Mickey would generally tell Minnie this. She rarely listened, though.
Took a Level in Badass: Mickey himself, repeatedly. Over the decades he's Taken A Level In Badass more than once, though thanks to the fact that outside the comics he's still largely viewed as the cute, smiling mouse, he's been particularly subject to Badass Decay — until a new generation of writers and artists show up and have him Re-Take A Level In Badass. The most consistent thing in the comics is turning him into a genius Amateur Sleuth (often with Goofy as his Plucky Comic ReliefSidekick), though some stories have presented him as a severe andrenaline junkie. The recent Kingdom Hearts representation of Mickey as a Badass Longcoat is really just one more instance in a long line of Badass levels for Mickey.
Vertical Kidnapping - This happened to Mickey in the beginning of Mickey Mouse Joins The Foreign Legion, a non-fatal variant which was actually a legitimate kidnapping.
Whole Plot Reference: Happened somewhat often, like in the Donald Duck comics: for example, one story was a Bowdlerized WPR of Misery (Mickey writes a novel series about an Expy of the Phantom Blot, decides to stop writing only for the Blot to kidnap him and force him to write one where he wins) and another was an equally Bowdlerized adaptation of Arsenic And Old Lace (with the old ladies being Robin Hood style thieves instead of murderers but with everything else remaining almost the same, down to the characters' first names)