Aunt Sarah

Aunt Sarah is the main antagonist (though she isn't purposely a villain) in Lady and the Tramp. She was voiced by Verna Felton and later by Tress MacNeille in the sequel.

Personality
The character that eventually became Aunt Sarah was softened for the movie, in comparison with earlier treatments. In the film, she is a well-meaning busybody aunt (revealed to be the sister of Darling's mother in the Greene novelization) who adores her cats. Earlier drafts had Aunt Sarah appear more as a stereotypical meddling and overbearing mother-in-law. Her singing ability is apparently non-existent. While she is antagonistic towards Lady and Tramp at first, she sends them a box of dog biscuits for Christmas to make amends for having so badly misunderstood them.

Lady and the Tramp
In the film, Aunt Sarah is in charge of Lady and the newborn child. While Aunt Sarah is upstairs, her two cats, Si and Am, cause trouble downstairs and wreck the house. Lady gains all the blame and ends up muzzled by Aunt Sarah, but Lady breaks free and runs away.

After Lady is taken to the pound, she is picked up by Aunt Sarah, but she ties Lady to her doghouse as punishment for running away. Lady soon spots a rat climbing through a hole in the fence. While she barks at the rat, Aunt Sarah tells her to shush. Tramp hears Lady and she tells him that there's a rat in the house. Tramp follows the rat to the baby's room and kills the rodent before he can harm the baby. The ruckus alerts Aunt Sarah who notices Lady and Tramp. Believing they want to harm the baby, she shoves Lady into the basement and forces Tramp into the closet. She then calls the pound and has Tramp taken away by the dogcatcher.

Upon Jim Dear and Darling's return, Aunt Sarah reveals that a stray dog, Tramp had been in the baby's room, and that she had him taken to the pound. After hearing Lady barking, they release her from the basement, where Aunt Sarah had locked her up. Jim Dear realizes that Lady is attempting to tell them something, and so he and Darling follow Lady to the baby's room. There, Jim Dear and Darling are able to find a dead rat. They realize that Tramp had been trying to protect the baby from the rat.

Lady and the Tramp II: Scamp's Adventure
Aunt Sarah returns in the 2001 sequel. She is first seen with Jim Dear and Darling, who are walking Lady and the Tramp and their four puppies: Scamp, Annette, Collette, and Danielle. She is later seen at an Independence Day picnic. Scamp disrupts the family's picnic by scaring Aunt Sarah's cats, Si and Am (who were hiding in a picnic basket, about to eat the family's chicken). Scamp then steals the family's chicken, determined to prove to Buster that he is a Junkyard Dog. The commotion agitates Aunt Sarah, as well as Scamp's entire family, including his father Tramp.

House of Mouse
Aunt Sarah appears in a cameo in House of Mouse.

Trivia

 * Verna Felton, who voices Aunt Sarah in the first movie, is the mother of actor Lee Millar, who provided the voice of Jim Dear in the first movie.
 * Aunt Sarah is usually never cited as a villain, being that she misunderstands things, such as not knowing her beloved Si and Am caused the trouble.