Unicron... definatly the biggest and meanest Transformer out there! I've had request after request for a custom of him but didn't know where to start. Should I do a repaint or rework the Armada one? Maybe turn Primus into a Unicron since he already had the planet spikes? Then it hit me while browsing the toy isle as I came upon these 'Neo Shifter' kits that rolled up into a ball. A planet-looking ball! They resemble Bionicle figures and I picked out the best Unicronish face I could from the different characters.
I used holiday icecicles for the planet spikes, Omega Red tentacles for the planetary rings, Patlabor/Microman armor where he needed it, and Chaos Lucifer's horns. The horns attach magnetically to the robot head or the planet surface. The chest grinder launches out (made from the wheels of something) and extends from the chest in planet mode so Unicron can eat him some planets. The eyes/forehead light up which I think is the coolest feature ever, giving him a really wicked look. You can even use it in Planet mode to light up the inside core of the planet!! Overall, favorite TF custom I've ever done. Thanks everyone for suggesting him!