The "Henry" to whom Ruff often speaks with on the phone is a reference to former WGBH president Henry Becton, Jr.
During filming of the series, Ruff's voice actor Jim Conroy would record his lines in an audio booth while ad-libbing to the contestants' reactions. After each shooting, he would then travel to New York City to record further lines for the animation.
First season contestant Taylor Garron was previously a cast member for the last season of the WGBH program Zoom (1997).
Seasons 1-3 featured a real-life basset hound named Murray working as an assistant for Ruff on the show. After the dog playing Murray passed away, though, the character was retired from the show and replaced by a bulldog named Tank.
All members of Ruff's extended family (Grandma Ruffman, Scruff, Great Uncle MacRuffmintosh, et al.) are all voiced by Jim Conroy.