Is it the same height as a normal player? If so, you need a mod like JediMod
which allows player scaling.
*cough* Well, I assume
JediMod allows it, I don't actually run any gameplay changing mods myself (just maps+skins), but I tried ones in the past for that very reason. They worked fine, but changed too much other stuff for my liking. I just can't remember which ones I tried, and I don't know which ones are the most popular these days.