2.6.4 Stage 4: Cerium
The first Labor: Nemean Lion.
This lion was invulnerable, his skin could not be penetrated by arrows. Heracles lured him into a cave and strangled the lion with his knees. He turned the lion’s skin into a garment that made him invulnerable. In Tyrens he showed the skin to Eurystheus. Hera placed the lion in the heavens as a constellation.
Stage 4: this is the first labor, the official start (Stage 4); the impenetrable skin of the lion is symbolic of the feeling of Cerium of being in a cocoon: it's impossible to go in or out. The skin of the lion makes Heracles invulnerable in his later works. This is symbolic of the Lanthanides being invulnerable in their mind.