|Current:||Cats of the Cressida Lock|
Trillion is a queen with an unknown description.
- Trillion is mentioned by Sparrow briefly, greeting Domino by calling him the boy of Trillion. Sparrow asks Domino if Trillion was a mouser like always. Sparrow later tells Trillion that she has earned her Pirrup title after uncovering a nest of mice during a bleak winter.
- Trillion scolds Domino for playing and not attending classes, and Domino follows his mother dejectedly.