Felicitas (also otherwise known as Felicity in English version of the movie) was a wise, beautiful (according to Francis) and perceptive russian blue who briefly befriended him during his quest to solve the first novel's case before meeting her untimely demise.
While escaping from the Church of Claudandus Francis accidentally falls into the apartment where Felicitas lives through it's skylight, the two cats speak and he quickly realizes that she is in fact blind, however this doesn't keep her from recalling the events around the block giving Francis vital information regarding the massacres.
During their conversation it is strongly implied that she was one of the cats kept in Dr. Preterious' laboratory and that her visual impairment was caused by one of the experiments. Despite this she seems content living with her current order despite taking a fairly sarcastic view upon human nature, either from the possible trauma beforehand or the fact many overlooked her due to her disability, it is unsure.
After first speaking with her, Francis goes on to talk with Pascal, this is when he receives the news that Felicitas has been murdered. She was brutally mutilated, having been decapitated and left to rot within her home, and not only upset Francis but also caused great grief in her owner within the novel.
- As aforementioned, Francis witnesses Felicitas' master shattered after discovering her body, showing that they cared for her. In the movie the master do not appear.
- Unlike most of the other cats murdered in the first novel, she was merely killed to keep silence while the others were to help keep the Felidae breed genetically pure.
- Her appearance and interaction with Francis in the movie, make Felicitas a popular character among fans, often portraying her romantically with Francis.
- In the novel, despite Francis valuating the she-cat as beautiful, there is no indication of romance and Francis himself is quite prone to physical attraction toward she-cats in heat (such as Nhozemphtekh).
- Only in the novel Salve Roma does Francis take up an official relationship with a she-cat by the name of Sancta, who curiously bears a similar pelt to the late she-cat.