• Gruntilda from Banjo-Kazooie is a rare female example. In addition to having green skin, she also shoots fireballs during the final battle of the first game. Subverted with Captain Blackeye, who was to be the Final Boss of Dream (the game that eventually became Banjo-Kazooie). In Banjo-Tooie, you can find him drowning his sorrows in Jolly Roger's Lagoon lamenting that "a bear and bird stole his glory". Gruntilda only shares her color palette(?) and fire powers with Bowser; Captain Blackeye is a Zero Context Example and the anecdote with his entry has nothing to do with the trope. Removed.
• Junkrat and Roadhog from Overwatch could be considered Decomposite Characters of this trope. Junkrat has a similar hairstyle and Evil Eyebrows, his explosives can meet the fire criteria, and the spiky tire on his back resembles Bowser's spiky shell. Roadhog is a brute of a man with an incredibly deep voice and Stout Strength. Both are vicious criminals who smash and destroy with glee. Junkrat and Roadhog are not final bosses, reptiles, or even antagonists in Overwatch unless you're specifically playing against them. They also don't have armies of minions the way Bowser does, and the physical resemblance seems to be Square Peg Round Trope. Removed as per the post directly below this one.
• Zavok from Sonic Lost World has huge fangs, spiky shoulders, Evil Eyebrows, and menacing claws. He's also the leader and the strongest member of the Deadly Six. However, despite being the weakest member of the group, Zazz has even more traits of this, such as his mohawk. Even his wild, brutish personality is more in line with this trope than Zavok's calm, ominous demeanor. This gets more ironic when you see both of them appear in Mario and Sonic at the Olympic Games. It sounds like these character mostly share aspects of their appearance with Bowser, and one has an attitude like him. But they don't sound like they fulfill the role that Bowser does. Cut Zazz, but not Zavok because he's included in the page image and I feel that the context would be removed for his inclusion. That's an issue that should be addressed in Image Pickin' so I won't get rid of the example unless the image is changed.
• Galvatron becomes this in The Transformers following the movie. Having lost most of IQ points due to brain damage, he trades in Megatron's tendency towards evil plotting for raw, uncoordinated beserker rage. Brash and boisterous, he acts more the mad king than military leader. His sleek, functional look gives way to a more imposing, armored design and the Decepticons are relocated to the castle ruins of the lava planet, Chaar. In response, much of the season focuses on new threats like the Quintessons and the Autobot-Decepticon War is presented in a much more one-sided manner. This sounds more like an example of Sanity Slippage and Mad With Power, but that could be because the entry focuses on his behavior and not his appearance, role in the narrative, and whether he has any minions or rivals in the way Bowser does. cut, apparently this one is the subject of an edit war?

To do next: examine the wicks.

• Indexes, image/source/etc lists, other places that aren't going to be wicks from examples.
• Links in sandboxes. I don't think we're supposed to mess with other people's sandboxes?
• 9 are part of the pantheon. I will check these later.
• 42 in character pages for works. I will check these later.
• A few in main trope pages. I will check these later.

Wicks I fixed myself

• Video Games potholed King Dedede from Kirby to King Koopa Copy, I feel this is a ZCE and as the series develops, Dedede isn't an example anymore.
• Video Games potholes Zavok from Sonic Lost World to the trope; this is another ZCE pothole. In addition, Zavok's status as an example is questionable.
• Two more ZCE character name potholes on Video Games R-Z.
• Examples from The Transformers and Wreck-It Ralph which were removed from the trope page have been removed from those works' pages.

Potential misuses

• Bonk: Bonk's nemesis King Drool is a massive, green, monstrous, Tyrannosaurus Rex with wings who kidnaps and brainwashes Princess Za in Bonk's Adventure. He just settles for world domination afterwards, though. In my opinion "Monster who kidnaps princesses" does not a Bowser Expy make, but if the character actually has powers or an army of minions or another strong similarity to Bowser, perhaps he counts. Never mind, he's probably a legit example.
• Frogger: Dr. Wani, the most frequently recurring villain of the games, is a large, green, suit-wearing crocodile. In some respects he looks like a less cartoony King K. Rool, himself a King Koopa Copy. Unless he shares powers, minions, royal status, or behavior with Bowser, Dr. Wani doesn't sound like an example. The detail that he's a "suit-wearing crocodile" seems to contrast with Bowser's punk rock-style appearance, and the title Dr. makes me doubt that he's characterized as brash and uncouth the way Bowser is. Removed.
• [[strike:Pollardos Feos Y Mazmorros: Mazmorro is a big, brutish and monstrous creature. Zero Context Example.
• Sonic Lost World: Zavok has huge fangs, spiky shoulders, Evil Eyebrows, and menacing claws. He's also the leader and the strongest member of the Deadly Six. I kept this, because Zavok is in the King Koopa Copy page image, though I cut the part about Zazz since I cut him from the trope page.]] Removed.

Webcomics

• Original Character Shenanigans: Boozer is the comics resident Bowser Expy. Sounds like a legit example based on the name but it is also a ZCE.

YMMV

• Sonic the Hedgehog: Zavok, the leader of the Deadly Six, is already disliked for being a Bowser ripoff with a generic "evil guy" personality, but fuel was further added to the flames when he started making appearances as a playable character in Mario & Sonic at the Rio 2016 Olympic Games and its sequel alongside Zazz, as a boss fight in Sonic Forces (whereas more popular antagonists like Chaos didn't get one), and as the playable Power-type member of Team Eggman in Team Sonic Racing instead of more fitting choices like Infinite, to the point of people calling him a Creator's Pet. As stated before, I left Zavok on the main King Koopa Copy page due to his presence in the page image.
• Sonic Lost World: The Scrappy: Zavok gets a large amount of hate. Aside from being a King Koopa Copy when many Sonic fans tend to dislike the series taking influences from Mario and not having much to his personality besides "generic evil guy", he went on to become a Breakout Villain and get more appearances over other, more popular villains.

• Citadel Of The Heart Grandis: An example not related to a video game, in that Grandis has more or less trained his Phase 2 form to more or less have very identical combat capabilities to Bowser himself, although whether or not Grandis even qualifies as a villain depends on who you ask. Much of the time, Grandis is typically an Aloof Ally at most in his more problematic situations. I don't think combat capabilities alone make a character an Expy of Bowser. Cut.
• Exalted Spirits: As if it wasn't bad enough that he looks the part, one of Octavian's greatest enemies is called the Mushroom King. Octavian looks like a semirealistic shark-man. His role in the story doesn't sound anything like Bowser's, either. Cut.
• Monster Hunter Fifth Generation Monsters: It's huge, ferocious, has two large horns and is lined with Spikes of Doom, has a Mighty Roar, and has a similar facial structure to Trope Codifier Bowser. The character is Nergigante, who isn't a cartoony monster nor does it command minions, hold royal status, kidnap princesses, etc. Cut.
• OK K.O.! Let's Be Heroes: Other Villains: She seems to be an Expy of Bowser. An Evil Redhead? Check. A yellow scalie? Check. Enjoys Playing with Fire? Check. An Extreme Omnivore? Check. Large and in Charge? Can be. The character is Cosma, who I'd honestly say is RIGHT on the borderline. She doesn't kidnap princesses, isn't royalty, isn't a final boss type, and lacks minions. However, there's an episode where the heroes encounter her as a giant in space, and there's myriad references to Super Mario Galaxy, including a scene where the heroes gather up space junk which resembles star bits and give it to her. In every other episode, though, her resemblance to Bowser is totally superficial. Clarified this one since I'm a fan of the work.
• Sonic the Hedgehog - Antagonists: Let's see. Guttural Growler voices? Check. Evil alien overload? Check. Power-hungry tyrant? Check. Have a lot of power? Check. Manipulating the protagonists? Check. Despite how they do it on different approaches. Monstrous final bosses? Check. Red and black color schemes checks? Large and in charge? Check. Yep. Even Black Doom has some similar traits to King Koopa himself, despite being slightly more cold, ruthless, villainous, intelligent and devilish. I feel like this one's a pretty easy zap unless there's something the example doesn't consider. This dude is a Black Cloak villain in appearance, so the physical resemblance at least is a stretch. Cut.
• On Sonic the Hedgehog - Infinite, Zavok's name potholes to King Koopa Copy. I haven't been nuking examples involving that character because he's in the page image for the trope.
• Sonic the Hedgehog - Solaris: Iblis is a reptilian monster made out of lava. He has fire powers and is very powerful, destructive and has green eyes and flame red skin. Not to mention he is evil in nature and is the final boss in Silver's story. Seems shoehorned. Cut.
• Star Fox Comic Characters: He's a reptile named after Bowser from Super Mario Bros.. Character is named Bowsor. The description above literally notes that "Despite his name, he does not actually resemble Bowser, though he is reptilian." Hmm.

Pantheon I'm not entirely sure how to handle Pantheon because it seems to be a Just for Fun thing, so I didn't cut any of these wicks even though they all pertain to characters I cut wicks for elsewhere.

• In Character Expies, we've literally got Zirek from Sonic Lost World as the God of Bowser Imitators. That's why there's a wick on Sonic the Hedgehog too. Man, is the discussion of this guy tethered to this trope!
  • Gruntilda is listed as a follower. I cut her other wicks because she's not an example.
  • Notes that like him Ralph is a King Koopa Copy, but since Ralph is a good guy even if he's a bad guy they usually don't get along. However he is fine with testing strength for fun or going to Bad A-Thons, as he has some respect for Ralph's strength. Ralph as in Wreck-It Ralph, another character whose wicks I cut because he is not an example.
• Regarding the Koopa Troopas from Mario', on Reptiles: They tend to gravitate towards Wreck-It Ralph due to sharing similarities to their own master. It helps that Ralph's a Punch-Clock Villain. Koopa Troopas can sometimes be found as enemies in "Fix It Felix, Jr" (when the enemies from Q*Bert aren't available). See above.
• Regarding the Boos from Mario, on Tics: Sometimes they can be found attending Bad-Anons with Wreck-It Ralph. They like him, maybe because he reminds them of Bowser. Three for three.
• Regarding the Toads from Mario, specifically the blue and yellow Toads, on Miscellaneous Flora: Given their status of being a duo that sticks together in any sort of situation (or simply being Those Two Guys), they have gotten along with other duos such as Bulk & Skull and Timon & Pumbaa. On the other hand, both Toads (and the other Toads by extension) prefer to keep their distance from Junkrat & Roadhog, especially after hearing how these two Australian menaces had a few characteristics in common with Bowser. I cut the previous wicks I encountered for Roadhog and Junkrat because they are not an example of the trope.