Western animation/M

Ma

 * Mao Mao: Heroes Of Pure Heart - S1EP04: "Ultraclops". After Badgerclops uses a device that turns him giant, Mao Mao and Adorabat use it too so they can convince him to stop using his size for petty reasons. (Note: Adorabat is the only female member of the main trio.)
 * Marcus Level - EP07: "Doctor Marcus". Marcus must help eliminate a highly contagious virus before it's too late. To the verse unable to cure his friend Ephy with the tools they gave him, Marcus decides to stop biting for one of the bacteria of the virus, causing the protagonist to shrink to enter the body of Ephy and eliminate the virus directly with his sword.
 * Mad - SE?-EP?: There’s a brief moment with a fat woman as a giantess eating cake.

Me

 * Mecha Builders: Mecha Abby can grow to be giant size.
 * Megas XLR - SE2-EP01: "Ultra Chicks". a magical robot girl (in which a parody of Sailor Moon) arrives on Earth to recruit Coop, but they mistakenly recruit Jamie because he lies claiming that he is Coop. Coop goes to the planet of the "Sailor Moon" to rescue Jamie. These heroines can transform into mechas (metamorphosed giantesses) and fight with the real Coop (driving Megas XLR). At the end, during the credits, a comic scene which shows Goat is having an appointment with a "Sailor Moon" (as a mecha).
 * Merrie Melodies - Those Beautiful Dames: Animation from 1934. A girl arrives until an abandoned place, where it is taken care of by several toys that come to life, among them there are dolls of men and girls small ones that interact with her (para-giantess scenes).

Mi

 * Mighty Magiswords - SE2-EP02a: "Fixing-a-Flonk!". Prohyas tries to help Flonk become a better comedian. Throughout the episode, Vambre warns Prohyas that she has little time to make Flonk a better comedian or take him to the police, representing herself as a moon that is approaching Earth as time goes by (being a reference to the moon of The Legend of Zelda: Majora's Mask).
 * Miraculous: Tales of Ladybug & Cat Noir: Parisian teenagers lead a double life as students and superheroes.

Mo

 * Mona the Vampire - SE1-EP17a: "Garage Sale Genie". Temujin the magic genie, turns into an mini-giantess.
 * Monica's Gang: O plano sangrento - EP4c: "Astronaut". During the search for the protagonist to get a girlfriend "from another world", one of the ones he found was a giantess who steps on him (only her foot can be seen). His fellow "alien" tells him: "Wow, what a big lady is there! She's big, she seems to like you, since you were the only one she stepped on".
 * Monsters vs. Aliens (TV series): an notable character of the series, which she can change size. Monsters vs. Aliens.

Mu

 * ¡Mucha lucha! - SE3-EP02b: "The Incredible Penny Plutonium". After an accident with some chemicals from his father's laboratory, Penny becomes a huge muscular imperfect giantess.

My

 * My Friends Tigger & Pooh - SE1-EP13a: "Super-Sized Darby". Darby accidentally becomes giant after being exposed by a magical plant growth potion.
 * My Life as a Teenage Robot: The daily life of a robot with typical female American middle-class teenager mentality.
 * My Little Pony: Equesteria Girls - SP3: "Mirror Magic". Juniper Montage becomes a Mini-giantess after trapping Sunset Shimmer.
 * Mysticons: In several episodes, there are para-GTS, but there are also GTS.