Unit Editing for scenarios(Help!)

I want to move units from the science fiction game to the fantasy game for a scenario

I replaced a unit with the transceratops by editing the units pic with paint(i backed up the units file so i didnt lose anything)

i edited it into the rules amd description and sound.

i know i am doing something wrong but i am not sure exactly what.

it has to do with the pic probably but idk how to make those "Unit.GIF"s and i would like to know how, pls halp