
The comic actor and self-confessed comic book geek admitted that he has a blast shooting the two-part episode, titled The Eclipse, with fellow actor Breckin Meyer because he's a huge fan of the show.
"I've been begging for a part on the show since it hit the air," he told TV Guide.
"It took me three seasons, but I did it!"
Seth, known for playing Dr Evil's son in Austin Powers film series and Daniel 'Oz' Osbourne in Buffy The Vampire Slayer, plays the owner of Sam's Comics, a seedy collector's shop, which Hiro (Masi Oka) and Ando (James Kyson Lee) walk into.
Masi revealed he was thrilled to have Seth join the cast.
"To have Seth want to be on our show is a real stamp of approval. It gives us fanboy cred," he said.
And there's talk that it won't be Seth's only appearance on the hit series.
"When we signed on, they said, 'if you guys do these roles, we need to know that we can get you back again if we need you', and we were like, 'Dudes, are you kidding?'" he said.
"We wanna keep coming back until our characters are so popular we get action figures."
Advert
No comments have so far been submitted. Why not be the first to send us your thoughts?
Bag all your glamour, gossip or even your next free ride to a favourite gig, right here. Plus go star-spotting and win our weekly glamour Friday night out below!
More here
After thousands of votes, Metro readers have finally picked their favourite celebrity for 2008! Look back at all the drama from this year... Find out the top 10 here...
We pick nine of the best and worst celebrity pictures. From Crazy Amy to Geek Chic - laugh or grimace at the celebs here
Beat the high street queues and bag a bargain online. Hundreds of goods including DVDs, iPods and cameras are on SALE. Savings of 20% and more!