Eddie is the dog owned by Frasier and Niles' father Martin, a large Russell Terrier. Eddie was played by two dogs during the run: first by Moose, and then by Moose's son Enzo, who first appeared as a stunt double.

Eddie is known for responding to Martin and Daphne with human-like understanding, but often seems to taunt Frasier. In one episode, Three Dates and a Break-up, Eddie eats the meals Frasier prepared for his dates as if he, Eddie, knew that Frasier's dates would not be staying for dinner. An early recurring gag had Eddie staring unceasingly at Frasier, often wanting something, to Frasier's increasing annoyance. Frasier's ex-wife Lilith is the only one who scares Eddie and whenever she's around Eddie does "exactly" as Lilith says.

Eddie is often featured in the closing sequences of a show, when the closing theme is played/ sung and the credits roll, in a short vignette generally related to a joke from earlier in the episode.

Eddie's birth date was originally given as May 7 but was then changed to May 15 in the final episode; Goodnight Seattle

Eddie's intelligence and capacity to learn tricks are very inconsistent, sometimes being incapable of learning to sit and at other times looking left and right on Martin's command. It was once shown that the only word he understands is his own name but other times he seems to understand exactly what he's being told.

In "The Unkindest Cut of All" a neighbor brings over a box of puppies that she claimed Eddie sired. Frasier, who had not thought that Eddie was entire, subsequently manages to give them away, and insists that Martin have Eddie neutered.

With 192 episodes under his belt and having worked since he was 3, Moose retired from showbiz when he was 10,[citation needed] in the year 2000. He was replaced by his similar-looking son Enzo for the final two seasons of Frasier; Enzo was 7 years old at the time he took over.

Moose died in June 2006 at his long-time trainer's home.