Gold Assassin

From Tardis Wiki, the free Doctor Who reference

The Gold Assassins, from the Court of Xones, were robots imagined in a humanoid shape. With a golden surface concealing their internal circuitry, they were ideally placed to be offered up as tokens to people of influence (and targets for assassination).

One such Gold Assassin, en route to assassinate the Empress of Altari, crashed on Earth and was damaged. While it shut down to facilitate its own repairs it was found and shipped across the Mediterranean as a gift from Marcus Antonius to Cleopatra. It awoke on board a Roman sailing vessel and continued its quest to complete its mission, mistaking Cleopatra for the Empress. It was defeated when a canister of mercury, on board the ship for Cleopatra, was used to corrode it. (COMIC: Golden Slumbers)