>>58361490
>the pre-evo was used for the substitute?
Well, the original Substitute from G1 and 2 used the same sprite as the statues, so it was technically Gyaoon. From Gen3 onwards, they swapped it's appearance to that of its pre-evo. Compare this Substitute Doll from Gen 3 with the back sprite of Gyaoon 's pre-evo on the left of >>58358514
After Gen3, they rounded out the doll's features a bit more and shortened the ears/horns to the more chibi version we're familiar with today, but you can see from the Gen3 sprite that it was originally a 1:1 recreation of the little guy.