Timothy honed his comedy writing and improvisational skills as a twelve-year main company member of the Groundling's Theater. He is also an accomplished dramatic actor and leading man. He is currently in pre-production on a feature film that he penned that is yet untitled. The movie follows a gifted medical doctor struggling to conceal his early onset Alzheimer's. Brennen wrote the film as a tribute to his father who was a Pediatrician and died from the disease in 2012. He also filmed his parents during the later years of his father's disease that became part of a documentary entitled "Jack of Hearts". Both films are due out in 2017.