tiny dog that yaps and tries to bite you and won't shut up. the idea is that any dog that can fit in a mailbox should be classified as a rodent. yapping is suggested in order to meet mailbox dog standards, but not required. see also puntable.
"that would be a fun bike ride if it wasn't for that f---ing mailbox dog at the end of it"
"yeah, that dog is such a puntable"