Bowser is the hulking, slow-witted assistant handyman to Bruno on Dog City. First appearing sporadically in the show's first season, Bowser became a regular thereafter, helping or often hindering his boss. In Eliot Shag's cartoon series, Bowser's counterpart is Bruiser, equally slow-witted nephew/henchman to Bugsy Vile. Bowser's species appears to be a St. Bernard.

Bowser's puppet is essentially the same as that used for Mad Dog on the original Dog City pilot of The Jim Henson Hour.