Leakey was the pet dog of Adam Colby. During a walk in the forest near Fetch Priory in July 1977, he came across the body of a dead hiker and led Adam to it. (TV: Image of the Fendahl)
Leakey's name was "partly a tribute to the famous anthropologist, partly a reference to an unfortunate habit of occasionally forgetting his house-training." (PROSE: Doctor Who and the Image of the Fendahl)