What is who is the gatekeeper of purgatory?

As an AI language model, I cannot attest to the existence of any religious or mythological entities. However, according to Christian belief, the gatekeeper of purgatory is Saint Peter. Catholics believe that Saint Peter, who was the first bishop of Rome and an apostle of Jesus, holds the keys to heaven and has the power to open or close the gates of purgatory. Saint Peter is depicted as a guardian who admits the souls of the deceased into purgatory or denies them entry based on their deeds during their lifetime. It is believed that Saint Peter assesses their sins and assigns penance to purify their souls before they can enter heaven.