Kilowog
Kilowog has always been my favorite member of the Green Lantern Corps.  I made him using a Darkseid base figure.  This custom requires quite of a bit of grinding and sanding.   First I used the cutting wheel on my Dremel to cut off the knee protectors on Darkseid's boots.  It took a lot of shaping to form them to the desired look.  I also ground off his gloves and belt. I cut away a good portion of his head.  I used Sculpey to build up his boots, to make his elbow length gloves and ring, and to sculpt his head.  When painting him I had a difficult time painting his chest emblem.  My wife suggested tracing it onto his chest using carbon paper, and then painting using the carbon outline for guidance.  This method worked very well.