Claudandus is an elderly Havana Brown cat and the true main antagonist of Felidae, the first novel and the animated movie from 1994.
A long time ago, he was a little stray cat found and adopted by the team of Professor Preterius, who performed painful experiments on him. He later took revenge on Preterius, killing him and with the help of Joker he planned to create a breed of cats named "Felidae" that resembled the primordial race of ancient Egypt in order to overthrow the human race. While Joker founded a religious group to worship the figure of Claudandus as a martyr, Claudandus himself took the identity of Pascal and kept on a breeding project to create the "Felidae". Claudandus killed many cats to prevent mating that could have altered the final product of such breeding project and exploited Jesaja to hide the bodies for a very long time.
It was only with his growing age and a diagnosed cancer that Claudandus started to make mistakes and Francis noticed the first body. He offers his help to Francis but later reveals himself, trying to persuade Francis to keep on his plan after his death.
After Francis' refusal and a bloody battle, Claudandus is killed by Francis and the "Felidae" project is destroyed: the cats of the "new and old" breed destined to mix together the other feline community.
Pascal used to be friendly when he helped Francis to solve the clues about the killer, often showing his sympathy for Francis. At end of the movie he reveals how his desire was to persuade Francis to keep on his plan after his death, having found in Francis a cat with similar intelligence and high moral values: the refusal makes surface his darker side, pushing him to attack Francis and showing in the last dialogue how the pain caused by humans led him to a path of hate.
- He is voiced by Academy Award nominee Klaus Maria Brandauer. His English voice over is John Hurt.
- Claudandus was neutered after his arrival in the laboratory, and the lack of a descendant may have caused his initial sympathy for a cat like Francis, that shared his intelligence.
- Claudandus means, "He who must be concealed/locked away" in ancient Latin.