Vincent Twice (or more properly, "Vincent Twice, Vincent Twice") is a parody of actor and Muppet Show guest star Vincent Price who was featured in Mysterious Theater sketches on Sesame Street beginning around 1989. His trademark was saying his name twice in succession.
Serving a role akin to Alistair Cookie or Phil Harmonic, Twice hosted the "Mysterious Theater" sketches, which were a spoof of Price's stint hosting the PBS series Mystery!, from his fireside armchair. He would usually stare at his lit candles, too, as thunder rumbled outside. Then he would introduce and close out each installment featuring Sherlock Hemlock and his dog Watson.
In his earlier appearances, Vincent Twice spoke and acted in a slower, more ominous tone. Later skits had Twice acting a bit more humorous. In one installment, "The Case of the Missing Toast," Twice himself is revealed to have stolen the toast (as well as a roast), and ominously suggests there may not be another installment.
In Episode 3033, as Maria attempts to find a missing sock on laundry day, Vincent Twice steps in, introduces himself to Maria, and introduces "The Case of the Missing Sock." Sherlock Hemlock and Watson come in, only to have Watson find and steal the sock. As they leave, Vincent Twice closes the segment. At the end of the episode, Vincent Twice announces the episode's sponsors in voiceover.