Egg Bro is a fictional troublemaker in various Go!Animate grounded videos, based on the Hammer Bros from Super Mario Bros. Aside from being a typical troublemaker like most Go!Animate troublemakers and a Super Mario OC, not much is known about him other than the fact that he likes to throw eggs at people.
Egg Bro appears in All Star Smashers as a Primary Spirit, as a novice class, where you must fight both Tabatha & Emrly and Sonny Slaven at McDonald's to obtain him. When fighting Tabatha, Emrly and Sonny, Sonny will favour using his neutral B move. Also, both characters' Final Smashes will be different from their usual ones. Tabatha & Emrly's will involve them cussing orders at McDonald's, while Sonny's will involve him saying "Loli" which almost always kills the player.