Darrius

Darrius was an elderly scientist who experimented on the plants in a jungle on Marinus, increasing their growth rate and making them more aggressive. He kept one of the keys to the Conscience of Marinus and made a fake key to fool anyone who tried to take it. Before dying, he told Ian Chesterton where he had hidden the real key. (DW: The Keys of Marinus)


 * Darrius was not named on-screen, only in the credits.