To TF pull the head apart at each side, and fold the halves of the neck down to the sides. Pull on the hips and they'll fold downwards under the body. Tail unclips, and then clips into the robot's hand as a morning star.
Articulation is mainly fore and aft joints, but he's still quite a nice little toy. You could easily imagine there being an army of these....
Undermine was released in Japan as Galaxy Force toy GD-08 Dino Shout with the bright green plastic a much brighter day glo shade and the darker green more an olive colour.
He comes with a beast planet key numbered s48r. Colourwise his body swaps dark green for black, the lighter green for yellow and the grey for red. It's a decent looking repaint bringing the original Repugnus to mind with the chosen colours.