Keswick with the Holler Collar. The Holler Collar is a device invented by by Keswick. This device is used to put people's voices on mute, for instance, Dudley Puppy, just to block out his voice for constantly yelling at all times. So far, it was only seen in Hush Puppy. Gallery Add an image Retrieved from "https://tuffpuppy.fandom.com/wiki/Holler_Collar?oldid=129264" Categories: Objects Keswick's inventions T.U.F.F. Puppy Community content is available under CC-BY-SA unless otherwise noted.