Starro

Starro the Conqueror is a high level DC supervillain and frequent enemy of Superman. Interestingly, he can be found in captivity in a hidden room of Seagate Amusement Park in Batgirl: A Matter of Family. Supposedly he was the main event in one of the park's many attractions as a poster advertising him can be found. However, as the park never opened, he remained in captivity, for the best considering his powers. Upon entering the room, an eerily droning sound can be heard.

In the main comics universe, Starro the Conqueror could create duplicate spores of himself that, when attached to people's faces, could control their minds. The presence of such an apocalyptically dangerous supervillain in the Arkham universe, while unexpected, matches the frequent references to Superman and other metahumans made throughout Arkham Knight.

Trivia

 * Starro was the first villain the Justice League fought, dating back in 1960 from the comic The Brave and the Bold.

Starro