Coach Sandoval Hines (Keegan-Michael Key) is a hypocritical, short-tempered, energetic, gum-chewing high school coach who works at a Catholic school and is the main protagonist of the sketches.

He is the quintessential stereotype of a high school gym teacher. He easily becomes upset by disruptive behavior from students during school events and threatens to kill and injure them in response, but ironically, is far more disruptive than the students he threatens. Principal Lankenstein (Ike Barinholtz) seems to dislike Hines for disrupting his speeches during school events and they end up fighting at the end of some sketches. He and Lankenstein are arch-rivals, as well as enemies. It is also implied that Hines had a troubled or neglectful childhood. He is also known for kicking his leg high in the air. Hines' comedic foils have included students like Joseph Yamanashi (Bobby Lee), Jeff DeShazer (Ike Barinholtz), Tommy Hackenjos (Frank Caeti), LePrince (Jordan Peele), Caraco (Matt Braunger), Darnell (Eric Price), and Morales (Johnny Sanchez).

His catchphrases are "Stop it or I'll set you on fire!", "I will stab you in the neck with a pencil!", and "Whaddaya laughin' at, Yamanashi?!". Numerous sketches involve a nun punching him out at the end. On the last episode of MADtv, it was revealed that he is actually an heir of the Heinz Ketchup fortune, but just decided to spell his last name differently so he could pose as a high school coach and inspire someone to do the right thing.