Ambrosius was the main antagonist in the book Cave Canem. He was part of a group of Wild Cats living in an abandoned house in the forest.
Ambrosius is cat colored in cream and golden tones. He has long, fluffy fur and bright green eyes. The main markers of his personality are his intelligence, which rivals that of even Francis, and his constant need to talk.
Ambrosius is one of the Wild Cats living in the forest. He takes an interest in Francis' investigations and poses as an ally, "helping" Francis come to his conclusions. However, it is later revealed that Ambrosius has a paw in the killings and was only obstructing the investigation. He is eventually killed by his own people, the Wild Cats, before they depart into their new lives.
- Ambrosius was an Somali Cat.