The Announcer

From Homestar Runner Wiki

This guy appears in "Marshmallows Last Stand" and "A Jumping Jack Contest," although his voice is heard in several subsequent cartoons (e.g. SBEmails "Mascot" and "Suntan"). He looks kind of like Coach Z with a monocle and a big moustache.

The barbershoppers who sing the Ballad of the Sneak, voiced by real-life band DaVinci's Notebook, are all lookalikes of The Announcer.

He can also heard in "The Reddest Radish" announcing that they should all bring their radishes to the staging area and as the narrator in the documentary in "The Search for the Yello Dello", though this time with an australian accent.