Domino is the son of Dottie and Dipstick, the brother of Oddball and Little Dipper, the grandson of Pongo and Perdita, a main character in the 2000 film 102 Dalmatians and one of the two protagonists of it's video game (the other one being Oddball).
He has two black ears with rows of white spots like a set of game dice, thus earning him the name "Domino." He also has a blue (live-action)/red (cartoon) collar that has a domino hanging from it. It is also worthy to note that Domino appears to have a lot of large black spots, as opposed to Little Dipper whose spots are more numerous and smaller.
Domino is born to Dipstick and Dottie along with his siblings.
He and his siblings are later captured by Cruella DeVille who wished to use them to make a coat.
Fortunately, Domino, his siblings are able to defeat Cruella and are reunited with their parents and their owner Chloe Simon.