Chrochoch is a male cat of the "new and old" Felidae Breed
He's only shortly mentioned in the book, he had mated with a she-cat named Chanel: she was pregnant by him and was killed by Claudandus to prevent the birth of cross-breed kits.
(SPOILER): After the death of Claudandus, Chrochoch as the other cats of Felidae, mixed with other common cats living their lives without the bloody selections of their offsprings done by Claudandus.
Trivia: As the other cats of the Felidae Breed, Chrochoch is probably not interested in the genetic purity of his breed and it's likely that he was not aware of the death of Chanel (another possibility it's that he was aware, but somehow kept to silence by the same Claudandus)