Mrs Twit... had a quite nice face when she was young. The ugliness had grown upon her year by year as she got older.
"But the funny thing is that Mrs Twit wasn't born ugly. She'd had a quite nice face when she was young. The ugliness had grown upon her year by year as she got older." - The Twits
Mrs Twit is horrible as well as ugly, and she is married to the equally nasty Mr Twit. The two of them spend all their time playing mean tricks on each other, and on the other unfortunate people and creatures that they meet.
Mrs Twit has a glass eye (that she adds to Mr Twit's water-glass so he knows she's got her eye on him) and a walking stick (that Mr Twit uses to convince her she's got the Dreaded Shrinks.)
Horrible as she may be, Mrs Twit is also the subject of one of Roald Dahl's best-known quotes. After talking about her growing ugliness, the story goes on to say:
"Why would that happen? I'll tell you why.
If a person has ugly thoughts, it begins to show on the face. And when that person has ugly thoughts every day, every week, every year, the face gets uglier and uglier until it gets so ugly you can hardly bear to look at it.
A person who has good thoughts cannot ever be ugly. You can have a wonky nose and a crooked mouth and a double chin and stick-out teeth, but if you have good thoughts they will shine out of your face like sunbeams and you will always look lovely."
I've got eyes everywhere so you'd better be careful.
Mrs Twit 1
Roald Dahl's The Twits