The ad by 4Creative shows Underdog, a dog with a man’s body, with his own chat show featuring celebrity guests who talk about their experiences of Channel 4.
The ad launches tonight between Crufts and Gogglebox around 9pm. It features well-known Channel 4 stars such as Ashley Walters, Derren Brown, Jon Snow, Michaela Coel, Alan Carr, Anne-Marie Duff and Rob Delany.
It was created by Jolyon White and Richard Biggs, and directed by Neil Gorringe.
Dan Brooke, the chief marketing and communications officer at Channel 4, said: "As well as explaining why it is unique, Channel 4 has always backed rising stars and, since everyone loves an underdog, this one’s elevation to chatshow host was inevitable."