Pearls are sentient fauna on Jove that inhabit Shells. Pearls have a short lifespan, and need to replicate themselves through reproduction in order to survive. Pearls are made of a sort of immaterial consciousness, that can survive on its own or in a Shell (or Human body).
Because of their ability to adopt a human body if they are more Dominant than the host, Pearls are, along with Fairies, sometimes considered a threat to Mankind. However, due to Pearl's relative scarcity, and lack of political cohesion, they are not considered a major threat.
To offset the death of the Prince, the Blood Princess secretly replicated the Prince's personality and put it in Pearl 2's Shell, Suppressing and destroying Pearl 2 (Pearl 2 survived the aftermath of the Collapse due to his private deal with the Champion of the God of Continuity), from which she replaced it in his corpse after securing it during the events of The Collapse. The Prince therefore, due to the Rules of Mating among the three species, can be considered more Dominant than the most Dominant sentient being on Jove, thus making him the most Dominant being on Jove.
3 Pearls of The Purge