The Big Four are a group of heroes and are the titular main protagonists of the entire Bee Shrek Test in the House franchise. They are a team and brotherhood of four powerful individuals who've banded together to have fun and protect the world from the various villains, terrorists, and other threats that constantly threaten either the innocents of the world or even Earth itself.
The Big Four is the name given to the four main characters of the series; Shrek the Ogre, Johnny Test, Barry B Benson, and Cory Baxter, who are all not only the main protagonists, but are also the four most powerful people in the world. Together, the Big Four go on crazy adventures from turning mudane events into chaotic funrides during a normal day in the House or traveling the world to stop global threats such as the Brotherhood of Chaos or even aliens. The group has more than just four members, but the four core members are what makes the group what it is and the world wouldn't be the same without them and their heroism.
Shrek is the Ogre and Ogrelord of the House and is the unofficial but de-facto leader of the group. He's a large, strong and powerful Ogre with a love of onions and a big golden heart for the people (or maybe the people ass) and his swamp. Being an Ogre, Shrek himself is the tank of the team and is the one to lead the way and charges right on into battle and is able to overpower large groups of soldiers in his charges.
Barry is the Bee of the house as well as its chief lawyer and public relations representative. He's a top-notch and professional lawyer who's been there to bail out the White House whenever it and its government representatives get into trouble. Barry was killed by the Old Big Four, but he was eventually brought back through resurrection and continues to serve as a member of the team and to keep the Big Four the Big Four.
Just a regular kid, Johnny Test is the wild card of the group. He's the one who uses the technology and acts as the soldier of the group as he to charges into battle, but uses more tactics than Shrek does. Johnny is dependant on his sisters' technology, but is also very adaptable and can easily sneak around enemy defenses and is repordetly have killed over a dozen enemy commanders via stealth.
The future head of the White House and future President of the United States, Cory Baxter is the political force behind the Big Four. Not only is he a regular kid and can play with Johnny in the House with various games, but is also knowledgable about global geopolitical affairs and thus, knows what dangers await the Big Four whenever they travel to foriegn countries so they can avoid capture and the consequences that will occur if they're caught.