Simpleton bachelor Fred Chaney (Goldthwait) inherits a buck-toothed horse named Don and one half of a stock brokerage firm from his dead mother. He discovers Don is a talking horse (who can also speak the language of several other animals) that belonged to his deceased father. His stepfather Walter Sawyer (Coleman) offers to buy out Chaney's share of the business for a paltry sum, but Chaney refuses. Instead Chaney returns Don to his talking-horse family in the countryside and claims his place as partner at the firm. Chaney takes over an office and begins working as a broker, much to the chagrin of Sawyer. Don the horse overhears a stock tip and calls Chaney, presumably using his teeth to dial the phone. Chaney acts on the investment advice and becomes wealthy overnight.