Canada becomes ground zero for all things geeky Thursday as Fan Expo kicks off in Toronto.

The pop culture extravaganza is expected to draw more than 125,000 gamers, comic book lovers and sci-fi, fantasy and horror fans to the city—and how could the fandom resist?

Now in its 20th year, Fan Expo is the largest convention of its kind in Canada, the third largest in North America, and boasts a star-studded lineup of celebrity guests.

Among those expected to attend: WWE and Guardians of the Galaxy star Dave Bautista; legendary comic creator Stan Lee; Lord of the Rings star Elijah Wood and Richard Dreyfuss, whose Close Encounters of the Third Kind is an extraterrestrial classic.

Storm troopers get to work

Darth Vader and his storm troopers helped kicked off last year's Fan Expo in Toronto. More than 125,000 fans are expected to flock to this year's convention. (Aaron Vincent Elkaim/Canadian Press)

Captain vs. Captain

Star Trek fans will also have a chance to compare their favourite Enterprise captains with both Patrick Stewart (Captain Jean-Luc Picard) and William Shatner (Captain James T. Kirk) scheduled to make an ensemble appearance.

"I'm going to meet with the whole cast of The Next Generation,"' Shatner told The Canadian Press. "I'm very fond of all of them and am looking forward to spending time with them."

CBC Arts reporter Eli Glasner is heading down to catch the crowds and the elaborate cosplay costumes. Watch for live coverage on CBC News Network.

Toronto's Fan Expo runs through Saturday. 

West coast fans will have to hang on for  Fan Expo Vancouver slated for April 2015.

With files from The Canadian Press