SMG4, Mario, Woody, SMG4's friends, Henry and Samantha, etc.
Drill Finger, SMG3, SMG1, The Toddler, ???, Nintendofan996, etc.
SuperMarioGlitchy2 AKA SMG2 is SMG4's brother. He looks like a blue version of Metal Mario and is pretty shivery. He's been mentioned multiple times. He makes his first actual appearance in the Super Mario Galaxy Longplay. Him and SMG4 get along well despite minor bickering.