Tricey

Tricey was the name given by the Doctor to a Triceratops he encountered on the Silurian Ark. Tricey behaved somewhat like a dog, fetching Brian's golf ball and enjoyed being pat by the Doctor. Tricey was used by the Doctor and his friends as a mount to escape Solomon's robots on one occasion. However, soon afterwards, Tricey was shot and killed under Solomon's orders to demonstrate his seriousness. The Doctor comforted Tricey as it died. (DW: Dinosaurs on a Spaceship)