Rock Arm is the legendary dimension-hopping warrior, and Ploob Diver's trusty companion. Equipped with the sacred weapon of mass destruction, "The Rock Arm" he is able to level the mightiest of trees with only a single flick. Rock Arm will always appear next to, or near Ploob. He used to be a lowly rock miner, being tortured and starved by the tyrant the "Rock Lord," but Ploob (after gaining the powers of the Ploob Pack) came to the rescue, and fought off the Rock Lord. Ploob then bestowed upon Rock Arm the legendary powers he wields now. Rock Arm has died multiple times, but is always revived by Ploob in the end, and every time Rock Arm comes back his power increases twofold. He enjoys eating dirt, pebbles, radishes, strawberries, marbles, clay, bricks, mugwort, and chlorine. It is said in the ancient prophecy, "When the universe is at it's darkest hour, a hero will arise. This hero will be accompanied by a man who has learned the ways of the mighty boulder, and they will save the universe." Rock Arm cannot speak properly, and usually responds to everything by saying "Muh." Nobody knows what "Muh" means, but Rock Arm says it anyway.
"muh... muh... MUH!" -Rock Arm