Quorus

Quorus was a prehistoric jungle planet which had giant, dinosaur-like creatures. (PROSE: Doctor Who Fights Masterplan "Q")

History
The Third Doctor and Jo Grant visited the planet. They encountered a dinosaur-like creature which attacked them. They also saw the Master, who was controlling the creature. Whilst there they stole some giant eggs for his plan to take over Earth. (PROSE: Doctor Who Fights Masterplan "Q")