It seems that most mums in games are either the sweet but irresponsible JRPG type ('Yes dear you go off into the woods and fight the Dark Lords of Hell. I'll make a cake for when you get back. Don't die or anything'), or outright hideous of body or mind. Or both. In the name of exposing gaming's dark Freudian underbelly, we chose to dwell morbidly on the latter.
From: Dante's Inferno
Hideous because: She neglects the traditional birthing process in favour of pumping torrents of toddlers out of her nipples. And they come out with knives instead of arms. Sigmund. Entire weekend festival. That is all.
From: Big Mutha Truckers
Hideous because: She has a face like a bag of spanners and a body like a slightly deflated sumo. And given the placing of that shadow, we're not entirely convinced she's wearing pants.
From: House of the Dead: Overkill
Hideous because: She's about 900 years old, gives her son regular oral examinations with her tongue, and after her death (having by this point mutated into a towering great horror of lethal motherly devastation), said son repents for his zombie-manufacturing misadventures by returning to the womb. Via exactly the same path he left by. And given the nature of their relationship, we doubt it's the first time he's tried.
From: StarCraft II
Hideous because: Although she's a fiercely protective mother (essentially operating as a hardcore defensive unit), she's protecting Zerglings. And we all know what a bumper crop of Zerglings leads to.
From: The Metroid series
Hideous because: She was once the biomechanical central computer for the Chozo, but eventually sided with the Space Pirates in order to wipe out said benevolent scientific space-hippies and start breeding Metroids. She was planning on using them to conquer everything in existence, but commited heart-breaking infanticide on the one that protected Samus at the end of Super Metroid.
Also, she looks like a turd on a stick jammed into the top of a long-dead chicken.
From: Gameboy Advances in Japan and nowhere but Japan
Hideous because: It's brilliant, but stubbornly refuses to be released anywhere else in the world, regardless of rabid global Earthbound fandom and its characters' appearances in Super Smash Bros. Brawl. Heartless bitch.