The sold-out festival is expected to welcome some 130,000 people over its four-day run. Besides offering comic books and video games, the convention boasts a big Hollywood element. "Captain America" will play at the convention before its nationwide opening Friday, and "Cowboys & Aliens" will hold its world premiere at Comic-Con.
In addition, stars from Steven Spielberg and Peter Jackson to the "Twilight" trio of Kristen Stewart, Taylor Lautner and Robert Pattinson will be on hand to present their latest projects to the Comic-Con crowd.
Comic-Con continues through Sunday at the San Diego Convention Center.