Tarnak's origins are not clear. Given his uniform, he appears to be a native of the planet Mars, yet his loyalties clearly lie with Ming rather than, as one would expect, Queen Azura. He is described as "Ming's first assistant" and even Azura states that Ming is Tarnak's "master". It is possible that when she formed her alliance with Ming, Queen Azura formally appointed Tarnak to be Ming's aide, and Ming then assured Tarnak's loyalty by promising him wealth and/or power for assistance in toppling Azura from the throne. Tarnak seems to share Ming's pleasure in scheming to see Queen Azura meet with unfortunate accidents, so his loyalty to Ming extends beyond formal duty. He may have had a previous grudge against Queen Azura which Ming was able to exploit to his own ends.
It is not impossible that Tarnak was a native of Mongo, already loyal to Ming, who traveled with him to the planet Mars. However, later events would cast doubt on this theory as Tarnak becomes concerned when he believes that Ming will destroy Mars. Tarnak's fear is such that this finally turns him against Ming and he attempts to kill him in the Disintegrating Room. This attempt initially appeared to be successful, but Ming somehow escaped and returned to Mongo.
Tarnak's eventual fate is unknown but having made enemies of just about everybody around him, his future looked bleak.
Tarnak was portrayed by the actor Wheeler Oakman.