sea scrotum

A "Sea Scrotum" is a week old shaven

prickly ball sack that resembles a young sea urchin

The "Sea Scrotum" is a weapon spiked ball mounted on the base of the shaft, resembling a sea urchin, usually with a long spike extending straight from the top and many smaller spikes around the base of the head. The spikes distinguish it from the prick, which can have, at most, flanges or small knobs.