Alternative Character Interpretation: Due to Itoi's penchant for leaving a lot of elements of characters' personalities, motivations, and stories implicit or merely hinted at rather than stating them outright, as well as the relative drought of direct interactions between major characters during the first two games, you can find any number of interpretations of just about any character in the series.
Cult Classic: The whole series has a strong fanbase even years after the release of all three games, and in spite of their poor sales and/or not getting released outside of Japan (until many years later).
Discredited Meme: Among the fangame circle, naming your fangame along the lines of "Mother /insert number 5 through 10 here/" has become this, thanks to a long list of parody fangames poking fun at people trying to follow the success of Oddity (then MOTHER 4)'s attempt at being an Original Flavour fangame for the series. It's gotten to the point that attempting to post such a game on the Starmen.net Forum, whether serious or not, will get you temporarily banned after posting it unless you change the name for it almost immediately.
Jerkass Woobie: Giygas is an alien menace hellbent on conquering the world, but has a rather pitiable past. Accidentally abandoned by his race on planet Earth as a baby, he was found by Ninten's ancestors, George and Maria, who proceeded to happily raise him as their own child, and Giygas grew to love Earth. However, George went behind his back and leaked the secrets of PSI, the trade of Giygas' race and their one weakness, to the government, which angered Giygas once he grew up, leading to him declaring war on Earth. After his humiliating defeat by Ninten and co. through the use of the Eight Melodies, the very same tune Maria used to sing to him as a child, he returns to Earth 10 years later and plots on using the Devil's Machine to grant himself Nigh-Invulnerability and spread his influence across the globe. Said machine, however, gives him invincibility at the cost of destroying his brain, causing him to ramble incoherently and constantly feel pain, leaving him, as Porky describes him, an Almighty Idiot. Because of his adoptive father leaving his race at risk of extinction, Giygas grew to be a global threat who lost his sanity in the process.
Jerks Are Worse Than Villains: Although Giygas and Porky have earned their spots as villains in the series, the most reviled characters in the series are Porky's parents for inflicting horrific abuse onto their eldest child and starting him down an extremely dark path that could've been avoided with some actual parental love. George and Wess have also earned some ire for their Jerkass actions despite never doing anything villainous.
Memetic Badass: The art style being what it is, it often overlaps with Memetic Badass Adorable. Ness and Lucas are strong kids with powerful psi, but fans would have you believe their bats could kill gods and Rockin'/Love Omega would damage the fabric of the universe if both were done at the same time. Princess Kumatora is joked to be a powerful spellcaster that other princesses of Nintendo franchises would do well to stay away from, even if the princess part isn't technically accurate. Cue jokes that the likes of Zelda, Lucina, and Palutena gave sighs of relief when she was clearly too powerful to join the Smash roster.
Flint qualifies too. He survives two PK Love Omega and is shown standing perfectly. Also helps he's dressed the same as Chuck Norris. Few would be brave enough to fight a cyborg T-rex with a plank of wood and a fang, even fewer would be badass enough to win! He's as Badass Normal as it gets.
Heck, Giygas is a meme unto itself! Whenever a Mind Screw occurs, MOTHER fans will bring him up.
Clay models means we totally mean business, guys. Explanation Among the fan work scene, there's a tendency to make clay models for fangames/ROM Hacks ala' what the main series does. Nine times out of ten, the clay models are often the only things that come from these projects, so as a result people often like to poke fun at it when the clay models are the only things revealed about the game/hack when announced. The only one that can possibly get away with this is Oddity back when it was MOTHER 4, thanks to doing it before it became common place to poke fun at the practice.
His nostril hair already has a vice grip on our heart! Explanation A further continuation of the above.
"No problem here!" Explanation The stock text whenever you press an action command on something that can't be interacted with, usually a wall or door the player can't open yet. The Mother series being what it is, there's a high probability there's something significantly wrong with the current situation, coming off as a bit of Black Comedy relief.
"Is Ness 'x'!?!" Explanation Based off of Game Theory's infamous "is Ness Sans!?!" video, any theory that involves the Mother games will inevitably have someone make this joke.
"Is Ness Varik!?!" Explanation The most common non-Sans variant is that Ness is Ares, the protagonist of Brandish, due to Ares, under his localized name of Varik, being the protagonist of The Halloween Hack and said hack bringing some implications that Ness and Ares are the same person.
Quirky Work: It's most apparent in EarthBound, which mostly keeps things silly and wacky outside of its infamous Final Boss. While EarthBound Beginnings and Mother 3 have their silly moments, they're generally far more serious in tone than EarthBound.
The cartoony style and odd sense of humor make it hard to believe at first that this is one of Nintendo's darkest franchises. On the other hand, those traits can serve tomake itevendarker.
To show how dark it is, the third game begins with the player character's wife dying, them having a mental breakdown, and one of their children going off to fight the creature that killed his mom.