The Master of the Trods was an individual who travelled to Trodos and reactivated the Trods which he found there. He became their new Master (replacing MacTaggart) and planned a special punishment for the First Doctor, John and Gillian for defeating them earlier. He drew the TARDIS to a planet on which he had constructed a city, where the Super Trod told them that the buildings were booby-trapped and that they were to avoid them using only their wits. However, the Doctor and his companions escaped through a hole created by an explosion and made their way to the Master's tower. He tried to kill them, but accidentally threw himself through a window and fell to his death. (COMIC: Return of the Trods)
Behind the scenes
The appearance of the Master of the Trods and his prior backstory with the Doctor leave open the interpretation that this character could in fact be an early incarnation of the Master. However, as Return of the Trods was written some years before the introduction of the Master, any similarities between the two are merely coincidental.