ary Andrews was a successful Wall Street attorney. He had money, prestige and power. But in winning the rat race, Gary had gone too far. One day while reading the paper he was mystically transformed into a six foot, upright, talking rat. His personality remained intact, but his outer appearance now matched his inner nature, and Gary was clueless as to why the change had occurred (although at various times throughout the series it was hinted that he would only revert to his former appearance with the transformation of his inner self.

Gary was able to hold on to his job at the law firm of Harrison, Camille, Beckett, & Weiss, but he quickly discovered the new challenges he would have to face in a world generally not accepting of giant rats. His loudmouth and largely clueless boss, Mr. Harrison - who was never sympathetic to his underlings - was even more inclined to threaten Gary with being fired at the drop of a hat. Worried about property values, the other tenants in Gary's co-op building, The Montana, held meetings to discuss possible ways to have their giant rodent problem evicted. Especially obsessed with Gary's ouster was Truman Pinksdale, president of The Montana Tenants Association. Truman sought any means necessary to get rid of his furry neighbor. He went so far as to call a rat exterminator, but got more than he bargained for when he hired Johnny Bugz to do the job. Bugz was even more obsessed with killing rats than Truman, in addition to being stupid and highly unethical. He continually extorted additional fees from Truman (generally bullying him with threats of physical harm) each time he failed to kill Gary. To the perpetual frustration of Bugz, his elaborate plans constantly went awry and innocent bystanders ended up being the victim of the bullet/spear/car bumper/etc. intended for Gary. Probably smarter than Bugz was his pet cat Boots, whose occasional "meow" could apparently be understood by Bugz and held significant meaning.

Despite the open prejudice he faced, Gary's values remained steadfast. To him, money had more value than people, and ethics remained a speed bump on the road to ever greater success. Perhaps the greatest victim of Gary's selfishness was his mother, who called him several times a day. Each one-sided conversation revealed the indifference he held towards her and whatever problem she was having (she seemed to be beset with outlandish problems). For example, in response to one call he suggested that if the fire reached her room she should crawl to the window and throw herself out, then hung up because he was busy.

If Gary had the appearance of a rodent, he also developed some of its sensibilities. He had a giant hamster wheel installed in his apartment and he became something of a connoisseur of fine cheese, often ordering specialty brands from Ye Olde Cheese Shoppe. The boy who delivered the cheese, named Bud, was a stoner who was fascinated with the giant talking dog who always answered the door. Inevitably, Bud was sent on his way with a five dollar tip and some sort of condescending instruction to go hurt himself, to which the clueless Bud would begin asking a question concerning talking dogs before the door was closed in his face.

As to the ultimate fate of Gary Andrews, that question remained unanswered. The series was cancelled after a single season of 13 episodes, with an inconclusive ending.