SuperMarioJustin4

SuperMarioJustin4, often referred to as Justin by the other characters, is one of the two main protagonists of the Slimey & SMJ4 series. He is a tall blonde-haired teenage kid who wears the clothes of the iconic Nintendo character Mario.

Personality
Justin is a hard-working user who uses Blender (an animation program) to make logos, with the 20th Century Fox logo being his favorite. Justin is often friendly and well-meaning, but he does have a more random sense of humor and can act brain-dead at times. Justin has a lot of interest in slapstick, much like Slimey, who is his best friend. However, he despises his Creepypasta counterpart SMJ4.blend1 as .blend1 despises him; they both share an incessant rivalry between each other. He's also known to break the fourth wall and go against the laws of physics. He also loves to pull pranks, especially the Scary Maze running gag, and the EAS Alert on Slimey. He is also known to do impersonations, most often Yoda and Mario. He is also a standup comedian.

Slimey
Justin and Slimey are best friends. They are both funny and have high interests in slapstick.

SuperMariaJustine4
Justine is Justin's twin sister and female counterpart.

SMJ4.blend1
Justin and .blend1 are archenemies. During the earlier seasons, .blend1 tried to hunt down and kill Justin as a plan of revenge. Now he is a more of a simple jerk towards Justin.

Slimey.avi
Despite not being friends, Justin and .avi get along very well with each other.

Trivia
His voice actor is Tom Kenny, who is well known for voicing Spongebob Squarepants, Fry from Futurama, and many others.