This photo is labeled as 'Happy Holly' the short-haired Jack Russell Terrier --- (Though, if you ask me, this is not a pure Jack Russell. It clearly looks mixed with Cairn Terrier or even a Westie, based on the shorter legs & smaller, pointier ears.
CHUCK -- Australian terrier mix, friend to Sam and Dean. Chuck lives with a struggling writer. He met the Winchesters after they had averted a crisis and basically saved his life. Chuck is generally intimidated by them but trusts them nonetheless.