Karl Sadeghi was a human musician on the colony world of Hitchemus.
After being caught and tortured by the native tigers, he developed a complete hatred for the species. When he was later in the control room of a dam being attacked by the tigers, along with the Eighth Doctor and Fitz, he opened the floodgates and drowned the tigers. Regretting his actions afterwards, he stayed on Hitchemus to work with the colonists and tigers to save the planet from impending disaster. He realised, though, he could never fully make up for his actions. (PROSE: The Year of Intelligent Tigers)