Peter's gets manly with a Grizzy Adams-esque beard.
"Brian Wallows and Peter's Swallows"
Season 3, Episode 17
A lot of guys have gone through the spontaneous decision to let their facial hair run wild, and Peter Griffin is no different. The only thing is, an endangered swallow inhabits his giant beard, and he has let the chirping bird live in his face. The Grizzly Adams inspired beard gives Peter a manlier look than normal, but this is a move that probably doesn't justify having to put up with birds using your facial follicles as a crib.