Professor Gerald Gooder was a slight man in his thirties. He always wore sunglasses to hide his inhuman eyes. His cover story was that he was a scientist working at the Freedom Corporation, having created the Freedom 1b, a time machine.
In truth, Gerald had been grown in a nutrient tank by the Master. The Master transferred his mind into Gerald with great effort. When the Third Doctor and Jo Grant began to investigate the Freedom Corporation, the Master used Gerald to lure them to the Freedom 1b, which transported them to the construct, leaving them both trapped. The Master released control of Gerald, leaving him brain dead. (PROSE: Freedom)