Cloacina is the Roman goddess of canals and the patron deity of Venice.
Cloacina was a goddess worshiped in the glory days of Venice, however though her worshiped waned she still maintained the canals of Venice. Her spirit was captured by a aged vampire lord known as Romulus Diovanni. With her disappearance, Venice's canals to become excessively polluted.
B.P.R.D. agents Elizabeth Sherman, Abe Sapien, Roger and Johann Kraus traveled to Venice to investigate any supernatural cause. Roger finding a neglected statue of her became entranced by her image. The four discovered Diovanni's involvement, however he incapacitated all of them except Roger and summoned the demon lord Shax. The vampire offered Cloacina's spirit in return for power. His offer was rejected with the demon demanding to be released. Roger managed to shattered the jar the goddess was trapped in, freeing her. After the vampire and demon had departed, Cloacina's spirit was last seen giving Roger a small smile.
Afterwards the canals of Venice returned to normal with the rest of the B.P.R.D. team taking a short break. Roger was seen sharing a bottle of wine with the statue of Cloacina by the canals.
Cloacina's spirit seems to have had an impact on Roger as his small version of his afterlife had a shrine dedicated to her.
Cloacina was the Spirit of Venice and had a symbiotic connection with her city. It was her duty to maintain the canals of Venice, and her disappearance nearly caused an environmental disaster.