Race With Two Possible Sizes

[chaoscowboy]

Sorry for another question so soon. The Mogogol, by Alluria publishing can be medium or small sized, chosen at character creation, and it's land and swim speed change based on the size, though otherwise it's identical between the sizes.

I'm thinking the way to do this is with a dropdown selection but I'm not certain if that's the best way of handling this or how the code would work. I've googled and searched the forums and found snippets of code but none of them really seem to work. I believe I'm misusing RaceSize.