Usurper

A Usurper is an individual who takes many forms and has many reasons; perhaps he is the scorned relative of some monarch or ruler who believes they should be on the throne, or perhaps he is a member of a court or citizenry that wants more power than they deserve, or perhaps he is just a very sneaky individual looking for trouble.

The thing all usurpers share in common is what they wish to achieve, namely the overthrow of a head villain, hero, or neutral character or organization. Often, a usurper wants to take a position of great power, such as that of king or queen, but some usurpers are content with smaller conquests. They may go to great lengths to achieve their goals and feign loyalty until they are ready to strike.

A sub-type of usurper is "The Starscream", who is often shown as the second-in command or, in the least extent, minion of the Big Bad in certain evil organizations. In some cases where the Big Bad believes that The Starscream is very incompetent and doesn't deserve to take their position, it later turns out that The Starscream possesses capacities that make them able to take their position by force.

Classic examples of Usurpers are Jafar in Aladdin, Scar in The Lion King, Zant in Zelda, Smaug in The Hobbit, King Ghidorah in Godzilla and Lord Cotys in Hercule.