The Other Mother, also known as the Beldam (which means witch), is the book's super creepy villain. From the very beginning, it's clear to both Coraline and the readers that there's something very, very off about this woman.
Adding to the other mother's creepiness is her lack of a solid identity. All we know for sure is that she's super old; after all, the three children who Coraline meets in the beldam's world have been there for years. Let's face it, people haven't been saying "art thou" for quite a while, so she must have kidnapped them forever ago.
Other than her age, though, the other mother is a total mystery. To be honest, we don't even know what she looks like or where she lives! Sure, she looks like Coraline's mom now, but in order to trap the other children, she probably looked like their parents (but with button eyes, of course). And she currently lives next door-ish to Coraline, but we know that she made that world herself: she's probably been hopping from place to place, looking for vulnerable children.
Adding to the mystery of the other mother is that she's pretty much two-faced. One side of her is the kind, breakfast-making type. She buys Coraline awesome toys and clothes, and unlike Coraline's real mother, she pays attention to Coraline and offers to play games with her. But this is all too good to be true.
Love can mean a lot of different things. In real life, we love our moms, but we also love a good piece of chocolate cake. The other mother doesn't want the mushy kind of love, she wants the "it's mine to enjoy" kind of love. She looks at kids, and everyone around her, as objects to control, and this type of love ends up destroying people. The other mother wants to possess the children she takes so completely that she actually steals their souls.
For a moment, we might feel sorry for her. Maybe all she wants is love, devotion, and the closeness a child has with his or her mother. But if that's what she wants, she's going about it the wrong way. Manipulation and abuse will never win you love. This is a lesson that the other mother learns the hard way.
In case you haven't noticed, the other mother is really, really mean:
"She will take your life and all you are and all you care'st for, and she will leave you with nothing but mist and fog. She'll take your joy. And one day you'll awake and your heart and your soul will be gone." (7.41)
That's pretty much evil in a nutshell, which is why it's fitting that her name (the beldam) means "witch." We usually associate witches in literature with evil, so we guess this name works better than something like, say, Sharon. Calling the other mother a witch also reminds us that she seems to have magical powers. It's not any old woman who can steal souls and stick them inside marbles, or send her hand off to do her dirty work. If she can do this, who knows what else she can do? Climb back up a well, perhaps? We prefer not to think about it.
Like those crazy people in the movie Inception, the other mother is pretty good at creating other worlds. Or at least copies of worlds. She never makes anything truly original: the worlds she creates seem to reflect the desires of the people she's manipulating. She makes Miss Spink and Miss Forcible young and pretty again. She turns Mr. Bobo's circus into a wild success. And she creates all sorts of things that might appeal to Coraline, from delicious food to a killer wardrobe.
But the other world really tells us more about the beldam than anyone else. Because everything there is her creation, the other world shows us how the other mother thinks about things. Basically, she gives everyone the superficial things that they seem to want, but she doesn't understand anything about love or family or friendship. Why didn't the other mother go to any trouble to make a big world? Well, because her world isn't really a world: it's a trap. You might have noticed that she's often compared to a spider (e.g., "Her other mother's hand scuttled off Coraline's shoulder like a frightened spider [4.121]). That would make the other world her spider web. Remember, though, that spiders themselves have to live in their webs, too. The other mother doesn't have anywhere to be except her small trap of a world – not a great a life she created for herself.