OMF-G1. He had a number of designs before this. This, however, is the start of the OMF numbering and the beginning of his evolution. From there he progresses rapidly.
OMNI Line-Up. As you can see he's already
hit 22 variations by the time of this picture.
OMF-G26 S1 Annie. This is the next important milestone. This is where he starts listing the PaB costs for each of his designs.
OMF-G31 Trinity. If you think all he does is bipedal mecha, guess again.
Check out his photostream. You will not be disappointed.