Animals feed
Not a crab
Horseshoe crabs are chelicerates, placing them closer to spiders and scorpions than to true crabs. Their familiar common name describes an appearance, not their evolutionary branch.
3
Octopuses have three hearts: two supply the gills and one supplies the rest of the body. Their oxygen-carrying protein contains copper and turns blue when oxygenated.
Cubes
Wombats produce distinctly cube-like droppings, shaped inside the intestine rather than by a square opening. Research links the shape to differences in the mechanical properties of the intestinal wall.