Colton Haynes ("Teen Wolf") has joined the cast of the CW's "Arrow," TV Guide reports. He'll play none other than longtime Green Arrow sidekick Roy Harper.

First appearing under the name Speedy in 1941's "More Fun Comics" #73, Harper has also been known as the superhero Arsenal and, for a time, Red Arrow. The official description for the TV version of Harper calls him, "a handsome, street-savvy, teenager from 'the Glades,' the harsh, poverty-stricken portion of Starling City."

It is also noted that Haynes will serve as a love interest for Thea Queen (Willa Holland).

"Arrow" also stars Stephen Amell as Oliver Queen, Colin Donnell as Tommy, Susanna Thompson as Moira Queen and Paul Blackthorne as Detective Quentin Lance. The show airs on Wednesdays at 8 p.m. ET/PT.

(Photo Credit: Brian To / WENN.com)