An app aimed at children that featured a voiceover making threats to cut them with a knife, has been banned by Google. Blaze and the Monster Machines was removed from the Google Play Store following complaints from parents.

AJ (also known as A.J.), is an 8-year old boy and the deuteragonist in Blaze and the Monster Machines, Blaze's driver and his best friend.

AJ is a science whiz and Blaze's best friend and driver! Together, Blaze and AJ laugh, solve problems, and make a true winning team.

In the Season 5 episode "The Blaze Family," Blaze reveals the he has a family: a mother, a father (with an unknown name) and a little sister named Sparkle (who could possibly become a future main character in the series).