The T-birds' logo.
The T-Birds are a gang of greasers who attend Rydell High School. In the first film, they consist of Danny Zuko, Kenickie, Doody, Sonny, and Putzie. In the sequel, they consist of Johnny Nogerelli, Louis DiMucci, Goose McKenzie, Davey Jaworski, and later Michael Carrington.
These boys typically wear black leather jackets with their logo on the back, jeans, t-shirts, and either boots or converse tennis shoes.