2. The Riddler
Infamously portrayed by Jim Carey in Batman Forever, The Riddler is one of Batmans most famous enemies. The Riddler is obsessed with puzzles, word games, and of course riddles. He is usually portrayed as a quirky smooth talker, with a knack for pissing off costumed heroes. In the video game, Batman Arkham City, The Riddler kidnaps Gotham City Police Officers and puts them in elaborate torture situations. The only way to get them out is by solving his riddles. This type of psychotic behavior would make a great adversary for Arrow. The Riddler doesnt have super powers; he is just a deranged genius who just wants to make the world suffer. This works well in Arrows dark and realistic setting. The Riddler can appear in multiple seasons of the show even if Green Arrow captures him and gets him arrested, he would just use his smarts to work around the judicial system and be out and about to terrorize the archer again.