The film opens in springtime, about a year after Charlotte has died. Her three daughters, Nellie, Aranea, and Joy, are now in the stages of adolescence, with Wilbur serving as a companion and mentor. Templeton has his own children to look after, and Gwen the Goose has just hatched new goslings.
During this time, Wilbur befriends a newborn lamb named Cardigan, who is shunned by the other lambs and sheep of his flock because he has black wool. Wilbur takes Cardigan under his wing and shows him the farm, the ways of animal life, and dangers for which to look out.
A few months later, the county fair arrives. Farmer Zuckerman loads Wilbur and Cardigan into crates before heading to the fair. There, Zuckerman sells Cardigan to another farmer, Mr. Hirsh, much to Wilbur's chagrin. Fern, knowing that Wilbur and Cardigan are friends, begs for Zuckerman to reconsider, but Cardigan is still sold nevertheless.
Wilbur becomes worried about Cardigan, and decides to go visit Cardigan to make sure he is doing alright at his new home. As she was born there, Gwen gives Wilbur directions to Mr. Hirsh's farm. Wilbur, knowing that he will get lost on the way to Cardigan's new farm, requests that Templeton guide him there, under the promise that Wilbur will babysit Templeton's bratty child. Templeton declines, believing it is far too late at night. However, Templeton soon changes his mind, in exchange for the promised babysitting days.
During the journey to visit Cardigan, Wilbur becomes hungry. He finds some blackberries to eat, which cause his face to turn purple. He then gets his foot tangled in some brambles, from which Templeton frees him in exchange for two more weeks of babysitting. Some bark from the trees comes and lands on Wilbur's head, making him look like a wild boar. A near hit by a truck then reveals that two other men have now seen Wilbur, and they resolve to warn everyone about the "wild pig".
The following morning, Wilbur makes it to Cardigan's, and the two are happy to see each other. After Cardigan tells Wilbur that Mr. Hirsh plans to shear him, Wilbur promises Cardigan that he will stay until the shearing is done.
Meanwhile, an evil fox named Farley comes and steals a hen from the barn, and Wilbur reluctantly tries to stop him after being encouraged by Nellie. However, Wilbur is unsuccessful, as Farley flees from the barn before Mrs. Hirsh arrives, and she sees Wilbur and thinks he was the one after the chickens. Fern notices that Wilbur has disappeared and alerts her uncle Mr. Zuckerman, while Wilbur requests that Nellie, Aranea, and Joy spin a message in their webs like Charlotte did. However, their efforts are unsuccessful, and Wilbur is chased off by Mrs. Hirsch once again. Wilbur is forced to abandon his promise to stay with Cardigan, much to their dismay.
Immediately after, Farley returns and attempts to raid the chicken coup once again, but it has been fenced. Farley then sees Cardigan and steals him from the barn, planning to eat him. Wilbur manages to trap Farley in a "pig web", while Nellie, Aranea, and Joy spin the word "fox" in their webs and Fern arrives just in time to save Wilbur. Aranea and Joy decide to stay with Cardigan, and the film ends as Wilbur fulfills his promise to babysit Templeton's children, to his dismay.
- "It's Not So Hard To Be A Pig"
- "Watch Out Wilbur the Pig!"
- "It's Good To Be Me"
- "Charlotte's Kids"