Mistaken for Murderer: Aunt Sarah's reaction to seeing the room wrecked and the baby on the floor, with Tramp and Lady happily in the corner. Sarah immediately accuses Tramp of trying to murder the baby and has him taken away to be put to sleep immediately.
Really Gets Around: Lady gives him a long list of all his ex-girlfriends and asks him about it. The only reason they got away with Tramp fully admitting his involvement with all these women in a movie released in the 50s was because the characters are dogs.
Red Is Heroic: After being adopted by the Darlings, Tramp now sports a red collar, which is meaningful considering how he killed The Rat.
Retired Badass: By the time of the sequel, Tramp has grown used to being a house pet, but still retains his old skills and street smarts and will not hesitate to use them.
Subverted in the comics (except sometimes for Fluffy, who found her siblings games "undignified" and didn't usually play with them). They usually enjoy spending time together. Just look at them together here◊.
Demoted to Extra: At the start of the comics, all the pups appeared. But as Scamp got more popular, he was the focus, and eventually got his own spinoff comics, while the triplets fell into obscurity.
In the sequel, the girls had little to no role in the movie.
Embarrassing Nickname: In the comics, Scooter, the only boy of the three triplet cocker spaniel pups, and the youngest of all four of the pups, was called the "Baby" only Lady and Tramp could think of a name. Thankfully he gave them an idea◊
Freudian Trio: Collette is the Superego. Annette is the Ego. And Danielle is the Id.
Gender Flip: Scooter. In the comics, Scooter was Scamp's younger brother. But in the direct-to-video sequel, all three cocker spaniel pups are female.
No Name Given: Pretty much played straight in the direct-to-video sequel. You only see their names in the end credits.
Intially they got the same treatment in the comics (except for scamp). However, overtime lady and tramp find names for the three. Fluffy, a prim and proper pup like her mother, and Ruffy, a tomboyish pup who loves to play with her siblings, were named after a female dog tramp once knew called "Fluffy Ruffles." Scooter, the shy younger brother of the girls and scamp, was originally called "Baby" until he scooted far on a slippery piece of ice on the lake, giving him the name Scooter.
Polar Opposite Triplets: Mainly in the 1955 comics. Fluffy tries to be proper and lady-like, like her mother. Ruffy is rambunctious and doesn't mind getting dirty. Scooter is shy, likes to lay around, and a bit of a scaredy-cat.
Proper Lady: Collette seems to developing into this the most.
Karma Houdini: The Siamese Cats get Lady in trouble with a Wounded Gazelle Gambit and go unpunished for the trouble they cause. They originally showed a bit more concern (as did Aunt Sarah) upon finding the rat in the house but this was cut.