He and Gabby are the only humans to appear in the whole show (until Santa Claus in the two Christmas episodes and Commander Megan first seen in Robots in Space). Judging by his skin tone, AJ might be Caribbean or African.

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).