There is a profusion of words and phrases used for dogs that are not purebred:
*In the United Kingdom, "mongrel" is the unique technical word for a mixed-breed dog, and is not a term of disparagement.
*North American owners (U.S.A. and Canada) generally prefer "mix" or "mixed breed", but "mutt" is also used, usually in an affectionate manner.
*In Hawaii, mixed-breed dogs are referred to as "Poi Dog", and in the Bahamas they call them "Pot Cakes" (referring to the table-leftovers they are fed).
*In Brazil and the Dominican Republic, the name for mixed-breed dogs is "Vira-Lata" (vira: to turn, to bring down; lata: tin can, trash can) because there are dogs without owners that feed on urban garbage on the streets and often knock over trash cans to reach the food.
*In some countries, "Bitsa" or "Bitzer" is common, meaning "bits o' this, bits o' that".
*In Newfoundland, a smaller mixed breed dog is known as a "Cracky", hence the colloquial expression "saucy as a cracky" for someone with a sharp tongue.
To complicate matters, many owners of crossbreed dogs identify them - often facetiously - by an invented breed name constructed from the parts of their parents' breed names. These are knows as "portmanteau" names. For example, a cross between a Pekingese and a Poodle is called a "Peekapoo", and a cross between a Poodle and a Golden Retriever is called a Goldendoodle. A famous example comes from the time that Queen Elizabeth's famous Corgis mated with her sister's Dachshund, and the resulting offspring were referred to as "Dorgis".
NOTABLE MIXED-BREED DOGS
* Old Yeller, a.k.a. "Spike" - When Frank Weatherwax, part of the famous Weatherwax family of animal trainers, first auditioned this big, goofy, yellow shelter rescue dog he had found for the role of Old Yeller, he was initially found to be too sweet and playful. Old yeller had to be able to act vicious for the part. After a little extra training, Spike nailed the part, becoming one of the most memorable dogs in screen history.
*Benji, a.k.a. "Higgins" - Higgins was a mixed-breed dog found at the Burbank Animal Shelter by legendary animal trainer Frank Inn (who also trained Arnold the Pig from Green Acres). Higgins had a long run on tv's Petticoat Junction, retired, and then came out of retirement four years later to star in a series of wildly successful Benji movies.
*Murray, a.k.a. "Maui" - Maui, a collie-mix, was originally found in a Castaic, California animal shelter by noted Hollywood trainer Boone Narr. Maui's first assignments came in TV commercials and as the backup for the top dog in the feature film, Bingo. His major breakthrough came when he was cast as the somewhat dim-witted dog Murray in the popular comedy series Mad About You starring Paul Reiser and Helen Hunt, which ran from 1992-1999.