The first is Road Pig. You see the alternate blue pants as opposed to the grey pants from the production figure. While these are interesting, it's doubtful that this figure was actually designed this way. The Dreadnok convention set was supposed to have three motifs among the members: a color for each faction. It's an element that did not end up getting the press originally intended for it, though. So, the colors are of less importance than they might have been. The blue figure may just be a color or mold test on their the plastic or paint applications. But, being full production level makes it a very interesting piece.
The next figure is an alternate Beach Head figure. You see the green pants versus the brown pants from production. This figure is harder to discern. It may be an early attempt at a color palette that was later changed to the brown.