Russula clavipes, also known as the Green Crab Russula, is a medium to large agaric that is considered a variation of the Crab Brittlegill (Russula xerampelina) and is often treated as the same species. Similar to its red relative, these mature mushrooms emit a fishy odor. When cut or bruised, all parts slowly stain a dingy yellow-brown. The mushroom can be found in both deciduous and coniferous woodlands and is often observed during the late summer and autumn months.

Cap convex, becoming later flat, with a broad, shallow depression. Surface sticky when moist, but soon dry; smooth - not streaked or warty. The colour is most often dark olive green or brown. The flesh is white but discolouring slowly yellowish brown to brownish or brown when sliced. Gills broad, initially attached to the stem, but may separate as they mature. Close, crowded, or slightly spaced, changing from white/creamy to yellowish-orange as they age. Stem more or less equal, dry, fairly smooth and solid at first, later spongy. It has no ring. Spore print creamy, yellowish, or orangish yellow.

Similar species include Amanita phalloides (Death Cap) which also has a green cap, but has a ring and is not a Russula.