August 6, 1986
Air Holes look similar to Warp Pipes from Super Mario Bros. and like them they spawn enemies and are sometimes used for warping around. They return in most 2D Metroid games.
In this humorous manga Samus mistakes an Air Hole for a Warp Pipe from Super Mario Bros. and tries jumping in it thinking of being sent to the next level, only to be hit by a Zeb. A scene of Mario entering a Warp Pipe is also shown while Samus is speaking.
This is considered a sub-universe link because Samus is talking about Super Mario Bros. proving that it's a game within the comic's universe. Her trying to use it doesn't prove that any element from the Mario series actually exist in that universe.
Mario VS Wario: The Birthday Bash
In the second Mario VS Wario comic, Mario and Wario are fighting over a "Samus Doll" that they want to give Peach for her birthday. In the end the only able to give Peach the doll is ironically Luigi.
Super Mario RPG: Legend of the Seven Stars
March 9, 1996
If Mario returns to the Mushroom Kingdom castle after first reaching Land's End, in the Guest Room he'll see Samus sleeping. Speaking to her she'll say she's resting up for Mother Brain, supposedly having just fought her battle against Mother Brain, the final boss of the Metroid series, or preparing for it. She will go away after the player completes Land's End.
Additionally, on the top of Booster's Tower there's a toybox full of dolls and one of them is a Samus doll.
Mario & Luigi: Superstar Saga
November 17, 2003
(originally this was going to be a In-universe link, but in the final version is just an Out-universe link)
In the Starbeans Café, Professor E. Gadd from Luigi's Mansion gives one of his inventions to Mario and Luigi everytime they mix a new coffee, for a total of seven different coffees. Originally, every item obtained was given to Mario and Luigi by a different cameo character (Wario, Fox McCloud, a biker from Excitebike, Link, Samus Aran, Captain Olimar and Professor E. Gadd) but in the end they only retained Professor E. Gadd. Samus' item was originally going to be an Energy Tank, but it was replaced with the Power Grip, that prevents the character from dropping the Hammer while defending, helping to counter attack.
Before being scrapped, sprites and dialogues for these characters were actually included in the game, and are still present in its code, but unused. For Samus' dialogue there only are lines for the cashier, not her:
- Whoa! A power outage?
Yikes! Samus Aran!
I see you're rocking and rolling as usual!
...Looks like your energy tanks are empty!
Sorry, but can't you give your Hoolumbian to Samus?
Oh! Feeling better?
Supposedly the "rocking and rolling" phrase is a joke on her coming in the café by rolling in Morph Ball form. Possibly, after drinking the Hoolumbian coffee she would flash as being charged up and then shoot a beam.
Since the Power Grip is an item/move used by Samus in Metroid Fusion and Metroid: Zero Mission the final game is still considered to reference the Metroid series, only weakly.
Metroid Prime 3: Corruption
August 27, 2007
If the Ship Bumper Stickers are unlocked, then stickers will appear on Samus' Gunship depending on what save data the player has on their Wii.
There are three different stickers corresponding to the same number of Mario games, and are:
- Super Paper Mario: Paper Mario's face.
- Mario Party 8: Star emblem.
- Super Mario Galaxy: Mario's "M" emblem, with the game's title in it.
See here for other available stickers.
NES Remix 2
April 24, 2014
Stage 11 of the Remix II challenges is based on Metroid, with the player controlling Samus, however the enviroment itself is made of blocks from the Mario series, specifically from Super Mario Bros.: The Lost Levels, and there are 10 coins actually based on the ones from Super Mario Bros. 3, and the objective is to collect them all in 100 seconds. The graphics are based on underground sections of The Lost Levels, with blue bricks and black background, but the level design is not based on any actual area from the game. The gameplay is just like in Metroid, with the Brick Blocks acting like breakable blocks, being destroyed by Samus's attacks, and they can't be destroyed or bounced by hitting them from below, unlike Brick Blocks in the Mario series, therefore the difference is only graphical. The background music is also from Metroid.
Super Mario Maker
September 10, 2015
Two of the unlockable costumes that Mario can wear in the game by using a Mystery Mushroom are based on Samus, specifically:
- Samus: an 8-bit design based on her modern design in the Varia Suit, rather than her actual Metroid sprite, when worn it replaces the sound effects with sounds from that game. Samus also turns into the Morph Ball when running at full speed.
- Zero Suit Samus: an 8-bit design based specifically on her appearance from Super Smash Bros. for Nintendo 3DS and Wii U, when collected the "Item Found" jingle from Metroid: Zero Mission plays.
Both costumes can alternatively be unlocked by using the respective amiibo from the Super Smash Bros. series.
Metroid Prime: Federation Force
August 19, 2016
Scanning Mario characters amiibo (either from the Super Mario line or the Super Smash Bros. line) unlocks respective paint jobs for Mechs to use in Blast Ball mode. The compatible ones are: Mario, Luigi, Bowser, Peach, Rosalina and Bowser Jr.
Copyrights for both series are held by Nintendo.