The Voyage of the Dawn Treader
How we cite our quotes:
"And we thought we'd rather be invisible than go on being as ugly as all that." (9.54)
We suspect that what the Dufflepuds really didn't like about the way Coriarkin transformed them into Monopods is that they didn't have any control over the process. They counteract their feeling of powerlessness by working a spell of their own.
She saw herself throned on high at a great tournament in Calormen and all the kings of the world fought because of her beauty. After that it turned from tournaments to real wars, and all Narnia and Archenland, Telmar and Calormen, Galma and Terebinthia, were laid waste with the fury of the kings and dukes and great lords who fought for her favour. Then it changed and Lucy, still beautiful beyond the lot of mortals, was back in England. And Susan (who had always been the beauty of the family) came home from America. The Susan in the picture looked exactly like the real Susan only plainer and with a nasty expression. And Susan was jealous of the dazzling beauty of Lucy, but that didn't matter a bit because no one cared anything about Susan now. (10.20)
Lucy is tempted to transform herself into an incredible beauty, even more striking than her sister, Susan. But this is a transformation that she senses just isn't appropriate for her. The narrator hints that, if she focuses only on making herself desirable, then whole nations will be torn apart by that desire. (Remember Helen of Troy whose beauty caused the Trojan War?)
"You see, it's only they who think they were so nice to look at before. They say they've been uglified, but that isn't what I called it. Many people might say the change was for the better." (11.21)
Coriarkin suggests that the Duffers don't know what's good for them. Although they've been very resistant to the change, perhaps they are actually better off as Monopods. Maybe each of us has gone through personal changes that we resisted at first, only to learn that we were better off in the end.