Moloch (Bus Stop!)

From Tardis Wiki, the free Doctor Who reference

Moloch was the personal bodyguard of Lithops, the President of Mars in the 27th century.

When the time assassins found the Tenth Doctor in the 21st century, Moloch attacked the mutants that controlled the laboratory containing the time machine, while Martha Jones reversed the time machine's controls, bringing the Doctor back to the 27th century. (COMIC: Bus Stop!)