Green Arrow Pilot Finds Its Merlyn In Colin Donnell

There are no heroes without villains, and in the case of Green Arrow, the emerald archer has no greater foe than his bow-wielding rival Merlyn. It appears that this rivalry will bleed off the paneled page and onto the small screen, too, as the role of Merlyn has just been cast in The CW's developing "Arrow" pilot.

Deadline reports that actor Colin Donnell has been hired to play Tommy Merlyn, described in previously released character breakdowns as follows: "28 years old and devil-smooth, Tommy is a trustafarian like Oliver, a spectacularly rich young man whose life revolves around parties, clubs, liquor and lots of anonymous sex. Unlike Oliver, he can’t seem to understand his former best friend’s sudden change of lifestyle and direction."

Merlyn is one of Green Arrow's most identifiable enemies. MTV News' very own Ryan Rigley described the villain's comic book counterpart as "the inspiration for Oliver Queen to take up archery back when he was but a young man." In the show, however, Merlyn and Queen will start off as peers, former best friends who find themselves at an impasse with each other. Exactly how that dynamic plays out in future episodes is something we're very much looking forward to.

With Donnell's casting, the main cast for the "Arrow" pilot is largely complete. Stephen Amell stars as Oliver Queen, David Ramsey is Oliver's bodyguard John Diggle, Susanna Thompson is Queen matriarch Moira with "O.C." veteran Willa Holland playing her daughter Thea, while "Melrose Place" breakout star Katie Cassidy is taking on the iconic role of Black Canary.

Tell us what you think of the latest "Arrow" casting news in the comments and on Twitter!