Great piece of art! I love all the little details. It says "No Kill I" on the obelisk in the middle next to the horta.
I wish there was a melkotian and a tholian on there somewhere. (I know the buoy and the tholian web spinner are there at least, but it would be cool to show the actual aliens too.)
Also, is there a tellarite on there? I can't find one. Or the little copper skin guys who wear a fez from journey to babel?