Trod 751

From Tardis Wiki, the free Doctor Who reference

Trod 751 was one of the Trods who were constructed in 2066 on the planet Trodos by MacTaggart to give himself power over the other colonists, secretly using them to enslave everyone. When the First Doctor, John and Gillian arrived on the planet, they were captured by the Trods, but escaped and deactivated them. (COMIC: The Trodos Tyranny)