Strong Mad's Chainsaw
From Homestar Runner Wiki
The chainsaw arrangement is similar to the Jackyl song "The Lumberjack", which features a chainsaw solo played by the band's lead singer Jesse Dupree.
The chainsaw can also be seen in use by a hockey mask-wearing ghost from Blistergeist in slumber party. He uses it to create large blisters on the hands in the third round of Clapping Party. It then made another appearance as part of the costume for the Foreign Object Brothers in yes, wrestling.
The chainsaw was featured in the email videography, when Strong Bad lists some of the many professions which have quotes around them. These jobs include "heart surgeon", "licensed technician", "poultry farmer", and "fireman", and all involve using the chainsaw in some way.