Bowser

Bowser is a giant turtle who is usually Mario's arch-nemesis. He is the leader and king of the Koopa Troop army, and likes to capture Princess Peach or try to conquer the world, although his plans almost always fail, and he often needs the help of SuperMarioGlitchy3. Bowser has been shown to have used other methods of destroying Mario as well, such as creating four Mario robots & giving people nightmares with a crystal stone.



Mario
Mario and Bowser are arch-rivals in the official Mario games. In SMG4's bloopers, they are still rivals most of the time, but the two sometimes cooperate when they have a common goal, like hating Peach or cooking (althrough the latter ended when Bowser tried to make a Ztar, which turned into a hamburger instead, causing SuperMarioGlitchy3 to go make a Ztar himself).

SuperMarioGlitchy3
Bowser and SMG3 are the main antagonists of many bloopers, often hatching plans to kidnap Peach or kill Mario and SMG4. Being the evil idiots they are, they often disagree and fight with each other. This inability to cooperate has led to many failed plans. The two only occasionally interacted until the blooper Two evil friends!, where they were forced to become partners by Bowser's boss.

Princess Peach
Bowser's most common evil plan is kidnapping Princess Peach. He has a secret crush on her, which is the basis of the plot of Bowser Cyrus - Wrecking Ball.

Trivia

 * He extremely hates smg3.
 * He is rarely the actual antagonist in bloopers, contrary to his true nature in Super Mario 64.
 * He can fly.
 * He loves Justin Bieber, just like Toad and Yoshi.
 * In The Adventures of Mario and Luigi - Ep. 4, he was in love with Princess Daisy.