Tim briefly dates Elaine. He is also from New Jersey.
In "The Mom and Pop Store", Jerry is unsure of whether or not he is invited to Tim's party based on the way Tim says to Elaine, "Why would Jerry bring anything?" George also takes a pencil to the party because he thinks there will be a lot of dentists there and he wants to ask if they can compare the teeth marks on a pencil he found in the Jon Voight car to see if he really was the previous owner.
Tim was labeled as a "re-gifter" in the episode "The Label Maker", when he gives a label maker to Jerry as a gift because Jerry gave him Super Bowl tickets, when Elaine realizes that it's the same label maker Elaine had given to him as a gift for not charging her for dental work.
In "The Jimmy", Tim irks Jerry by having Penthouse magazines in his waiting room and by possibly 'violating' him while he was unconscious during a tooth filling.
In “The Yada Yada”, Tim converts to Judaism, and Jerry confesses to Tim's Catholic priest his belief that Tim has done this solely to make jokes (which offends him, not as a Jew, but as a comedian). Tim takes extreme exception to a joke Jerry tells the priest; as a result, he deliberately prolongs an uncomfortable procedure on Jerry. Also in this episode, Cosmo Kramer coins the term "anti-dentite" after the term anti-Semite. Dr. Abbott, the dentist who taught Tim, stands up for him at the wedding of his son, Mickey, and he chastises Jerry for antagonizing Tim. He says, “Tim Whatley was one of my students, and if this wasn’t my son’s wedding day, I’d knock your teeth out, you anti-dentite bastard.”
In "The Strike", Tim gave out Christmas gifts that were actually donations made in their name to a charity. This leads George to conjure up a fake charity called "The Human Fund", and he gives out fake Christmas gifts. Also, at Tim's party, Jerry meets Gwen, who is a "two-face", looking very pretty in some environments, but not so much in others.
A blog dedicated to the legality of the issues that arise in Seinfeld episodes, Seinfeld Law, has analyzed many of the classic Tim Whatley moments as they might have played out in a court of law.