Wow, cute in a weird way. I'd put that fish in a palace, feed him/her up and see what happens. Might make a good study for the effects of positive fishkeeping.
(I thought of the name Spike when I saw that tail!)
One of my first tanks had a guppy with a hunchback upside down "V" spine. She outlived a lot of her normal looking siblings and had no problems (and normal babies!) I named her 'Vee.'