Giarrusso created the Mini Marvels comic strips, featuring Marvel superheroes as children, which have appeared as back up features in many Marvel comics. The various strips were collected into Rock, Paper, Scissors and then featured in Mini Marvels: Secret Invasion.

Giarrusso also created G-Man and an all-new cast of kid superhero characters in the Comic Bits comic strip first published by Image Comics in the pages of the Savage Dragon comic series. The first G-Man digest collection, G-Man vol. 1: Learning to Fly, was released in May 2009. The first full G-Man mini-series, G-Man: Cape Crisis, is a five-issue monthly mini series that began publication in August 2009.

Comics work includes:

• Giant Size Mini Marvels one-shot (48 page single-issue comic, December 2001, Marvel Comics)
• Spidey and the Mini Marvels one-shot (32 page single-issue comic, April 2003, Marvel Comics)
• G-Man one-shot (64 page single issue comic, December 2004, Image Comics)
• Mini Marvels: Rock, Paper, Scissors digest collection (96 pages, August 2008, Marvel Comics, ISBN 0785132112)
• Mini Marvels: Secret Invasion digest collection (96 pages, February 2009, Marvel Comics)
• G-Man: Volume 1: Learning to Fly digest collection (96 pages, Image Comics, May 2009, ISBN1607060876)
• G-Man: CAPE CRISIS mini series (Five 32-page comics, August 2009 - January 2010, Image Comics)
• Mini Marvels Ultimate Collection graphic novel collection (216 pages, December 2009, Marvel Comics)