He has said that "once you start talking like [Julius Kelp] it's very hard to stop. On each take, I'll make it sillier, I always have. I'll add more and more stupid noises and sounds to it. If they let me keep going, it gets ridiculous." As a homage to Lewis, Azaria conceived the idea of the "Treehouse of " segment in which Frink revives his dead father, with Lewis guest starring as the father. In a review of that episode, which aired around Halloween in 2003, Robert Bianco of "USA Today" wrote that it is hard to tell Frink and his father's voices apart: "Azaria voices Frink with such a spot-on Lewis imitation that it's sometimes hard to tell which one of the two nutty professors is talking." In addition, "The Knoxville News-Sentinel"s Terry Morrow commented that "to hear Lewis doing Azaria doing Lewis is a mind-bending gut buster, the kind of pay-off that die-hard "Simpsons" fans live for." Frink is a popular character on "The Simpsons" and he has received acclaim from critics. Mark Hughes Cobb of "The Tuscaloosa News" named him his favorite secondary character from the show. "Fort Worth Star-Telegram"s Robert Philpot called the professor one of the five best supporting characters on "The Simpsons", writing that "Springfield's mad scientist is a triumph of style over substance, with Hank Azaria giving him a ripoff Jerry Lewis voice that reminds you why we once thought Lewis was funny." On their list of the top twenty-five peripheral "Simpsons" characters, IGN's Eric Goldman, Dan Iverson, and Brian Zoromski listed Frink at number fourteen, commenting that he fits nicely into the "Simpsons" universe "as the town's brilliant mad scientist." They highlighted a scene from the episode "The PTA Disbands", in which Frink becomes a kindergarten substitute teacher and keeps one of the children's toys to himself because the children "wouldn't enjoy it on as many levels" as he did. Nick Griffiths of "Radio Times" named Frink one of the best characters of the show, stating that he has "always loved Professor Frink", particularly because of his appearance, gibberish talking, and overuse of the word "the", and because of his inventions such as the matter teleporter that turns Bart into half-human half-fly.