Big Dog is a gigantic white dog from Go, Dog. Go!. He also his friends Little Dog, Paw Barker, Grandpaw Mort Barker, Tag Barker, Gerald, Manhole Dog, Clifford, Meathead, Horton, Lalo, Gajah, Pluto, Astro, Junior's Father, Dollar, Truant Officer, Trusty, Bear, Ruff, Baylene and Pinkfong.
He was voiced by Matthew Mucci.