>>51631559Because of the way she moves, her lost look, and her now purple color, I always associate Jynx with The Groke from Mummin, a series that is very popular during Christmas in Japan, cups, plates, cards. Obviously I am forcing these concepts.
But realistically it was most likely chosen because during Kanto she was one of the few options to be used as an elf (I would have chosen Mr Mime) or just the association with Santa just because of the color of her dress, as well as they used Ponyta for Santa's sleigh just because there were so few beasts of burden. Some time later Delibird and Stantler were created, so it was unnecessary to continue using Jynx and Ponyta.