Echo Kellum has joined the cast of Arrow season 4.

The American actor will play DC Comics character Michael Holt, aka Mister Terrific, on The CW series. Producer Greg Berlanti first revealed Mr. Terrific would appear on the show at San Diego Comic-Con last week.

"Ever since I was a young Blerd, I've always dreamed of playing a super hero," Kellum tweeted Friday. "Let's go Mr. Terrific!! @DCComics. Special thank you to @RapaportCasting @GBerlanti @mguggenheim @AJKresiberg @CW_Arrow and all the fans! I won't let Star city down! #letsgo."

In the comics, Holt is a technological savant who made millions with his firm Cyberwear. He assumed the identity Mr. Terrific, originally held by Terry Sloane, after the deaths of his wife and unborn child, and possesses genius intellect and a suit that renders him invisible to electronic detection.

Kellum will first appear in episode two, and the season will see the character work alongside Felicity Smoak (Emily Bett Rickards) at Palmer Technologies. Band of Brothers actor Neal McDonough has also joined the cast as villain Damien Darhk.

Arrow premiered in 2012, and will return for a fourth season Oct. 7. The series follows billionaire playboy Oliver Queen (Stephen Amell) as he becomes the vigilante known as Green Arrow, and inspired spinoff The Flash and the upcoming Legends of Tomorrow.