Slag Brothers

The Slag Brothers, Rock and Gravel Slag, are main characters in the Wacky Races animated franchise. Their voices were originated by Daws Butler and Don Messick, respectively.

They're known for being the drivers of the Boulder Mobile (designated #1).

TV series

 * Wacky Races
 * Wacky Races (2017)

Movies

 * Scoob! (drawing)

Shorts

 * Wacky Races Forever

Comics

 * Wacky Races
 * Hanna-Barbera Presents
 * #2A "Madcap Manhattan Motoring"
 * #2B "Trekking to Tanzania"
 * #7A "Desert Victory"
 * #7B "The Jaded Japanese Jaunt!"
 * Cartoon Network Presents
 * #7A "Drag Racing"
 * #11A "Fair Play"
 * #15A "Drive and Driveability"
 * #15B "Media Madness"
 * Wacky Raceland

Books

 * The Wacky Races Handbook

Video games

 * Wacky Races: The Video Game

Development
According to their original model sheet drawing by Jerry Eisenberg, their original names were Nitty and Gritty.

Behind the scenes

 * There is a whole civilization of cave-like people who look like the Slag Brothers (led by Captain Caveman) in the theatrical film Scoob!