I think in my game the award for the oddest makeover goes to Tina Traveller (Sims 2), whom I once gave a new look that was inspired by her getting electrocuted.
The new look:
https://64.media.tumblr.com/7e98edd5cdb4e844556db0b6aa18993a/tumblr_n7lbxvlVE61t1fm14o3_250.jpg
The whole sequence: https://enkisstories.tumblr.com/post/90928893104/well-tina-didn-t-you-know-being-a-criminal-is-a
A more recent makeover is that of Morgyn Ember. Magic is not real in my rotational save, but aliens are, and so I retconned Morgyn to Sixam's leading geneticist/genealogist. I didn't do this "makeover" myself, all I did was press a button in MCCC, but, voila - alienified Morgyn.
I kept bodyshape and skincolor, but added minor details like cc eyes, freckles, tatoos and a scar. None of those details shows up in their human disguise.
Headcanon also says that Morgyn was a boy for most of their childhood. When the day came to present their disguise to their classmates (disguising being something this generation was taught in school), they came out as nonbinary for the first time.
https://abload.de/img/28.06.20_01-32-59onjvf.png
https://abload.de/img/28.06.20_01-34-248ajue.png
https://abload.de/img/13.07.20_22-39-44ixjd2.png
https://abload.de/img/13.07.20_23-21-29xrk8r.png
