Green Lion (Leo Viridis): Often refers to the crude, corrosive solvent, the "universal menstruum" or the alkahest, which is derived from the Prima Materia. It is the initial, powerful dissolving agent, associated with the early stages of the Work (like the nigredo and albedo). It can also represent the philosophical mercury in its unpurified state.
Red Lion (Leo Rubrum): Represents the fully perfected, fixed philosophical sulphur, the final stage of purification, associated with the rubedo and the production of the Philosopher's Stone.