When the two factions of Felis sapiens built their arks and left Red Dwarf, they left behind anyone who was sick or injured in some way. One of those left behind was a priest of the Red Hat faction, abandoned because he was blind. He had one hand that was black, while his skin was mostly pink.
The Cat became the sole carer for the elderly priest, who eventually became the only other survivor of his race aboard the ship. The Cat would often leave the priest alone for days while he explored the ship. Over the years, he kept faith with the teachings of Cloister the Stupid, wearing the holy custard stains and the sacred gravy marks. His religion insisted that he renounce coolness in favour of slobbiness. After so long without any sign of his God, the priest began to lose his faith, convincing himself that Cloister wasn't real. He ordered the Cat to burn his sacred hat, a symbol of his priesthood.
When Lister started to study the Cat race, he followed the Cat down to the cargo decks through Supply Pipe 28 and was amazed to find the priest, whom the Cat had never mentioned. When he heard the Cat Priest railing against his God, he entered the room and managed to convince the blind priest that he was Cloister and that this was his triumphal return, wearing the doughnut and the golden sausage.
Lister showed the priest that his faith was not misplaced, and told him that his place in Fuchal, the Cat afterlife, was assured and graded him an A+. He even managed to return the priest's hat, which the Cat claimed to have destroyed. The priest declared this to be a miracle, but his joy was short-lived as the excitement caused him to drop dead from a heart attack (RD: Waiting for God).