- You may be looking for Turlough's school chum, Ibbotson.
A hippopotamus — commonly known as a hippo — was a large, Earth-native mammal that spent the bulk of its time in bodies of fresh water in jungles. The Second Doctor and Jamie McCrimmon once used a herd of animals — which included hippopotami — to stampede a group of Quarks. (COMIC: Jungle of Doom)
According to the Legend of Sutekh, the hippopotamus was among the animals associated with the titular Osiran god of evil and violence, Sutekh. Other animals associated by the Egyptian tradition with the cult of Sutekh included crocodiles, donkeys and pigs. (PROSE: Background)