Trisha is a sentient triceratops[1].
Trisha works in the Office of Subterraneaneal Temporal Accounting, managing a portion of the Fate Web for Father Time. She deliberately made accounting errors that allowed dinosaurs to continue living in The Valley that Time Forgot Lost in the Center of the Earth, ostensibly in retaliation for Father Time's "one personal item only" office policy. Once Father Time discovers this, he fires her and initiates measure to drive the remaining dinosaurs extinct.