Tigella
Tigella was a jungle planet in the Prion system that neighbored Zolfa-Thura. Native flora included the carnivorous Bell Plants.
It was inhabited by the humanoid white-haired Tigellans, who utilized the Dodecahedron as a power source. The structure of Tigellan society was based on two castes: the scientific Savants led by Deedrix, and the religiously fanatical Deons led by Lexa, who worshiped the god Ti.
The Fourth Doctor and Romana II visited the planet in 1980 and fought Gaztaks while Meglos retrieved the Dodecahedron. (TV: Meglos)
The Sixth Doctor once sang about his adventures, mentioning Tigella among the planets he'd saved. (AUDIO: Doctor Who and the Pirates)