The lower body/palanquin/slug section is hand sculpted from Super Sculpey around a floral wire armature and foil bulker. It’s a bit hard to see as I’ve concentrated the photos mostly on the upper body, but there’s a slug/salamander type pattern worked into the sides and back of the lower body.
The billhook/axe head is from the Chaos Knights sprue, the basis for the sludge cannon is from the Chaos vehicle frame, specifically the combi piece for the bolter.
The upper body was proportionately based on two Space Marine torsos, but is entirely from greenstuff. The head started out as the Nurgle Aspiring Champion head from the standard Chaos Marine squad, but took on a life of it’s own. Lower arms are based on Terminator arms, and the uppers are normal sized.