Washboard
From Homestar Runner Wiki
A washboard, as seen in the Homestar Runner universe, is pictured as a musical instrument which is stroked with a xylophone mallet or other implement.
This homemade instrument appears in two versions in the Homestar universe: The Homestar Runner plays "a mean worshboard" (labeled "worsh it!") that Stinkoman assumes is some kinda robot, and Saddy Dumpington (Strong Sad's 18th century persona) wanders the land spreading sadness and misery with one hung from his neck.
