1901
Drawing of Mario, Yoshi and Toad by Shigeru Miyamoto, from the British Official Nintendo Magazine.
1902
According to the manual for Mario Clash on the Virtual Boy, Big Boos are female. Since regular-sized Boos are often referred to as male, this could imply that female Boos are usually bigger than male Boos.
1903
Graphic for the hidden Luigi ice sculpture found in a cave in level Frosted Glacier-3, "Fire and Ice", of New Super Luigi U, extracted from the game's data.
1904
Here are QR codes for the Nintendo 3DS and Wii U. Thank you very much to reader @Alexand15684871 for the discovery and Mii expert @HEYimHeroic for the extraction of the data and preparation of the codes. The Miis are named "Mariwo?" and "Mr. NOA" internally.
1905
Limited edition Japanese "Mario Silver" Nintendo 3DS XL, featuring an emblem of Mario and Luigi reading "We are twins! We are twins! Super Mario".
1906
According to the Nintendo Power DKC2 trading cards, Donkey Kong's favorite quote is "I have but 99 lives to give for my Country".
1907
Super Mario Bros. Deluxe contains a calendar spanning AD 1 to AD 3000, yet by using a system called the "proleptic Gregorian calendar", all dates prior to October 15, 1582 have retroactively been assigned different days of the week, making it inaccurate for historical purposes.
1908
In Super Mario Galaxy 2, the background of Bowser's Galaxy Generator appears to be a gigantic castle hallway (top left). However, this is merely a perspective trick. The hallway and columns are not 3D models, but instead merely a texture covering the inside of a large sphere.
1909
The title screen for Yoshi on the NES contains four different versions of Baby Yoshi across the versions, one unused. Below is a showcase of the sprites and where they appear.
1910
Wrecking Crew '98 for the Super Famicom, a Japan-only sequel to the original Wrecking Crew, features a rice ball as a playable character. Here are the rice ball's sprites, profile pictures and victory scene graphics.
1911
An Easter egg in Super Mario Odyssey allows Mario to pass by the Tostarenan doorkeeper without a poncho by wearing the Skeleton Suit. However, his text does not change; even if Mario wears the Invisibility Hat with the Skeleton Suit, the doorkeeper will comment on his clothes.
1912
@GoddammitBaz The background was a crumpled sheet of paper with additional arrows and comments; it is provided below. Thank you very much for your inquiry!
1913
During Yoshi's licking animation in Super Mario Sunshine, he starts extending his tongue one frame before opening his mouth. In the first frame after starting a lick, Yoshi's tongue appears to be coming out of his nose.
1914
In the microgame "How the West Was Really Won" in WarioWare: Smooth Moves, failing results in the cowboy's underwear being revealed, which features Super Mario World power-up sprites. In-game, this is partially obscured by the timer; here is the graphic extracted from the data.
1915
The manual for Super Mario World states that Yoshi was named after Yoshi's Island, and not, as usually assumed, the other way around. This raises the question of how Yoshi's Island got its name originally.
1916
Wario Land 4 ending pictures only visible when completing the game in Super Hard mode while collecting all treasures.
1917
The largest in-game size disparity between Mario and Luigi can be seen in Super Mario Bros. Deluxe cutscenes, where Luigi is 30% taller than Mario. By comparison, Mario and Luigi's standard 3D models' heights only differ by 11%.
1918
Beta screenshot of Shifting Sand Land in Super Mario 64 from Electronic Gaming Monthly magazine. In addition to featuring a different pyramid design and course layout, Mario's mustache is a different shape from the final release, taking up more vertical space on Mario's face.
1919
The data for New Super Mario Bros. U contains an unused pepper level icon (left), meant to be used alongside other icons for secret levels (examples on the right). Since all secret level icons reflect the level's contents, it was likely intended for a unique pepper-themed level.
1920
Officially licensed Mario alarm clock. Unlike most clocks that use cartoon characters' arms as clock hands, this one does not display Mario's full body, instead choosing to make his arms emerge from his head.
1921
In the SNES version of Mario is Missing, one frame of the animation of Luigi crossing the road while riding Yoshi is heavily distorted, likely due to being created using a scaling algorithm and not drawn by hand as the other sprites.
1922
During the ending to Super Mario Sunshine, we briefly see Mario from FLUDD's point of view (top). There is a small window in the bottom left of this screen saying "Game Over". This appears to be a recreation of the Game Over screen from Mario Bros. on the NES (bottom right).
1923
In Luigi's Mansion, Luigi's cap is see-through from the inside. This can be seen most easily in the intro to the final boss battle, where the cap flies off Luigi's head in shock, and due to the transparency, appears briefly to resemble a visor.
1924
Illustration on the packaging of a 2014 licensed "Wario with Mystery Accessory" figure. While the figure itself has Wario's regular face, the illustration shows him without rings around his eyes and with a nose that is not red, bringing his facial color scheme closer to Mario's.
1925
In Super Mario 64, removing the darkness at the bottom of the hole in the Rolling Rocks room in Hazy Maze Cave reveals that it is directly above Dorrie's underground lake. A death plane was placed in the hole to prevent Mario from falling through into the lake.
Additional obscure Mario content for suppermariobroth.com.
Now on Patreon: patreon.com/suppermariobro…