Role in the film
Tyco first appears as a puppy along with several other black puppies sold for free in a box. One by one, the puppies are adopted by children and their families until Tyco is the only one left. Then, one stormy night, Tyco is still left behind and not adopted so he decides to abandon his box home to go out and live on the streets.
A year has passed and Tyco has grown to be a stray struggling for survival on the streets. After being shooed away by someone, he shares food he finds in the garbage with another stray until Animal Control shows up and tries to catch him. Tyco causes a mess at a market place as he is being chased by Animal Control until they finally manage to catch him and take him to the Central City Animal Shelter in Bedford, which is facing financial troubles. At the shelter, a girl and a volunteer named Emily Watson befriends and names him Tyco; much against the owner, Mr. Dudley's rules about naming animals at the shelter. When Emily mentions she taught Tyco a new trick, Tyco only ends up nearly tearing the owner's shirt by accident.
A few days later, a 13-year-old kid and one of Emily's classmates named Calvin Wheeler comes to the animal shelter and decides to adopt a dog. Knowing Calvin for being a bit of a schemer and someone who thinks that animals are dirty (as mentioned by Emily when he refused to hold her puppy in the 3rd grade), Emily suspects he's up to something but Calvin, using his wit and cunning nature, persuades her otherwise. Thinking this could be an opportunity to find Tyco a good home, Emily introduces Calvin to Tyco, who takes a sudden liking to him and starts to play Tug o' War with his shirt (a game he likes to play as mentioned by Emily). Emily instructs Calvin not to feed Tyco any Royal Hound dog food products or enter him in a dog show and that she needs a parent/guardian signature from him on the adoption papers, which he later tricks his mother into signing since his parents won't allow him to have a pet (not even a goldfish).
Later, Calvin asks Emily if he should be worried about germs but she assures him that "a dog's mouth is cleaner than a human's"; a fact Calvin "finds very hard to believe" when he catches Tyco drinking out of a toilet. Emily also gives Calvin her home number in case he has problems with Tyco and that she will come by in 10 days for a standard post adoption interview just to make sure he is fit as Tyco's owner. Then, Emily reminds him that he is now responsible for Tyco. Then, Calvin tries to teach Tyco on how to pull him on his skateboard with his leash but to no avail. However, Tyco, seeing some other dogs with their owners, starts running and pulling Calvin a little faster than expected, which ends with Calvin falling into a lake.
Then, Calvin asks his best friend, Raymond Figg a.k.a. Figg to keep Tyco for a few weeks at his place; much to Figg's reluctance. However, Figg returns Tyco to Calvin at night when he finds out that his landlord only allows pets which weigh a minimum of 7 pounds at his apartment complex, otherwise, it would mean eviction, so, Calvin finally decides to take him in his room. Inside, Tyco tries to take and probably play Tug o' War with one of Calvin's covers from his bed until Calvin takes it back and tries to teach and get Tyco to sleep on the floor. Everything turns out okay until Tyco decides to sleep next to Calvin on his bed; much to Calvin's annoyance due to Tyco's snoring.
The next day, at the park, Tyco is seen with Calvin sitting on a bench as he listens to Figg about the rules in the rule book concerning the Bedford Civic dog show held in in 2 weeks where he plans to enter Tyco in in order to win $5,000 first prize so as to buy the last of the Gotham Man comic book to complete his collection as part of his scheme from the very beginning. Then, Calvin's archenemy, Preston Price comes along and starts mocking him and Tyco and threatens to "destroy" them at the dog show; thinking that "dog shows are out of Calvin's league." Then, he warns Calvin "to drop whatever scheme he's planning with Tyco." Luckily, Tyco comes to Calvin's defense by going around Preston, having him tied and stranded to his leash, and then, dragging him in the mud. Calvin and Figg try to get Tyco to stop but to no avail. Even Preston calls for his dog, Jacques' help but it doesn't work either.
Calvin and Figg take Tyco back home to get themselves cleaned up and later, start to have fun when playing with the water hoses altogether. They even manage to hide Tyco in the small pool when Calvin's mother arrives. At night, Tyco keeps Calvin up again with his whining and whimpering.
In the morning, when Calvin leaves for school and forgets to feed Tyco, Tyco decides to enter the house and start eating all the food he can find in the kitchen and fridge while causing a huge mess. When Calvin returns to find the kitchen messed up, he tries to catch Tyco until he finds his parents having arrived home early, so, he tries to hide Tyco under a cover and takes the blame and responsibility; much to his parents' shock and yet astonishment when they see that their son didn't make any excuses, didn't blame anyone else, and finally took responsibility for anything as he usually does. Calvin then takes Tyco to his room without getting caught. After cleaning up the mess, he finds Tyco having chewed on his sneakers and eating his geometry homework and scolds at him. His scolding almost gets him busted with his mom until he tells his mom that he's "just doing his nightly meditations."
The next morning, Calvin ties Tyco to a tree in his yard and decides to take him back to the pound after all the mess he caused. But when Calvin finds out that Preston paid a couple of guys (and somewhat "friends" of his) named Leonard and Thrash to beat him up to make him and Tyco stay away from the dog show and encourage him to drop out even if Calvin promises to take Tyco back to the pound after school, Tyco breaks free from and with the tree he is tied to on a leash, breaks through the fence, and rescues Calvin from the two would-be trouble makers. This rescue later changes Calvin's mind about the pound and allows Tyco to stay. At night, Calvin calls up Emily to see if she can help him with Tyco since he finds that "he's a little bit more than he bargained for." The next day, at the park, Calvin tries to get Tyco to sit until Emily arrives and teaches him the proper way through food, encouragement, patience, approval, and love. Then, they all spend some time having fun at the park.
Later, Calvin's secret about Tyco is out when he and Figg find his mom home early and having found and barricaded "a bear" in his room. When she tries to call 911, Calvin finally reveals the truth. After his parents have a long discussion at night about Tyco, they finally accept Tyco since having a dog was proven to be something good for Calvin and that "love doesn't have any shortcuts." However, Calvin is punished with no T.V. or cellphone for 2 months due to tricking his mother into signing the adoption papers for Tyco and is told to improve his grades at school.
Calvin starts to feed Tyco as a first step of responsibility and then clean up after him. Tyco can be seen eating Calvin's ice cream as he and Figg are reading Gotham Man comic books. Later, during a stormy night, Tyco starts to have a flashback from his past about how he was left behind as a puppy, which makes Tyco whine and whimper until Calvin assures him that he is completely safe with him.
The next day, at the Royal Hound's Obedience and Obstacle Dog trial, Calvin and Figg try to make an entrance for Tyco while avoiding being seen by Emily and seeing that Calvin is still in one piece and with Tyco and Figg, Preston tries to get them nearly kicked out due to Tyco not being properly groomed as he sarcastically wishes them "good luck" until Calvin calls up his friend; Rondel, his teammates, and his mother, who is a Beauty Salon hair dresser, to take care of Tyco's grooming.
At the trial, both competitors compete with their dogs through the obstacle courses and despite Tyco having caused a bit of a mess and a few time penalties, Calvin and Tyco are declared the winners with Tyco earning the nickname "Tyco the Terrible" and making it to the Top-Dog finals. Preston tries to angrily protest when believing it to be unfair and accusing Tyco of cheating. When Preston thinks that he and his dog will be impossible to beat according to a lady reporter during a small press conference, Calvin simply replies with his famous motto: "Expect the impossible."
Later, Emily arrives for the interview as she and Calvin are being "served some pizza" by Tyco. After playing Nintendo, saying yes for being asked to the Spring dance, and seeing Calvin with Tyco on T.V., Emily finally realizes Calvin's scheme, rejects going to the dance, and angrily leaves him when she refuses to believe that Calvin has somewhat changed, has a heart of gold, and he really loves Tyco since he refuses to not enter Tyco in the finals. Then, Figg arrives and finds posters of Tyco on the streets; claiming he is "a lost dog named Chester already belonging to a family", thus, forcing Calvin to give up Tyco to his "family". Calvin asks Figg to take down the posters but he refuses. Then, Calvin takes Tyco back to his real "family", refuses the reward money, and asks them to take care of him; much to his reluctance.
When Figg arrives on the day of the Royal Hound Top-Dog finals to see Calvin and finds out he "did the right thing", he goes to see Emily at the shelter and explains what happened until Emily discovers that the photo on the poster matches exactly like the one she took when Tyco was first brought into the shelter. When they tell Calvin the truth, he finally realizes it was Preston behind the plot and that Tyco's "family" were actually a couple of people he hired and paid to pretend that they were his real "family" as a way to exact his revenge for his humiliating defeat at the trials.
Tyco is seen locked up in the phonies' basement until Calvin and Emily rescue him while Figg provides a distraction by pretending to sell magazines and faking an asthma attack. Then, Calvin's parents drive Tyco and the kids to the finals. After Preston and his dog have finished their routine and score a 98, he is shocked and surprised to find Calvin and Tyco back just in time before their disqualifications. He even tells them that it will be impossible for them to beat his score but Calvin refuses to listen and continues anyway. Seeing as to how incredibly well Tyco and Calvin are performing with the whole skateboard-pulling routine through the dog obstacle courses, Preston, worried that Calvin will win and refusing to admit defeat, takes his dog and decides to take matters into his own hands by sabotaging one of the dog obstacle courses during the show. Nevertheless, Calvin and Tyco still win, beat Preston's score by one point, and get a 99/100, and Preston gets disqualified for the sabotaging. Tyco can be seen accidentally breaking Calvin's skateboard in half, which he caught when Calvin fell and landed on the judges' table due to the sabotage, after their victory.
Along with using that reward money to buy the last comic book, Calvin uses the money for good. He gives the money to the shelter (where Tyco used to be) so that the dogs can have better homes. In the end, the shelter is saved and Figg along with many other people adopt a new pet. When Figg adopts a Chihuahua named Rufus and seeing how well he is performing with him, Calvin tries to talk Figg into teaming up with their dogs as a tag team with him as the manager "to help count all the money" for next year's competition. Tyco is made a hero for having saved the shelter after that.
- Tyco is about 168 pounds if he is 24 times over the 7 pound limit for pets at Figg's apartment complex.
- Tyco isn't actually named Tyco until he is brought into the shelter and taken care of by Emily mostly a year later. Emily, being the tritagonist, is the first one in the movie who ever calls him Tyco - otherwise, he is called "mangy (or filthy) mutt", "stupid dog"; much against Mr. Dudley's rules about naming animals at the shelter. One interesting note is that Emily actually calls Tyco by his name once before selling him to Calvin.
- At the beginning of the movie, the box of free puppies in front of the store, children come and take the black puppies while the golden puppy Tyco is left in the box but then a boy took one but there was still a black puppy left in the box.
- The plot of Life is Ruff is similar to Oliver & Company; in both beginnings, the baby animals (puppies in Life Is Ruff, kittens in Oliver & Company) are in a box for free. All of the baby animals are picked but the main animal protagonist (Tyco;Oliver) runs away to become a stray. Later, the main animal protagonist is adopted (in Life is Ruff, it's Calvin, in Oliver & Company, it's Jenny) but a rich person temporarily takes them away. At the end, the owners and pets are reunited.