Anti-Villain: He does thievery and has the dogs do his dirty work, but he does care for them. Plus he's justified in his paranoia his dealings with Sykes and the welfare of the dogs if he gets "sleepin' with the fishes".
Cowardly Lion: He does crimes to escape his possible gangster death punishment from Sykes, but he does try to fight against him once he goes too far.
Jerk with a Heart of Gold: A difference shared with the film adaptation - yes, he's a thief, and was planning to ransom Oliver, but he clearly loves his pets, and when he learns that Jenny is Oliver's owner, he immediately gives up all idea of collecting the ransom (even though he is fully aware that he will be killed if he fails to pay Sykes) in order to return Oliver to her.
Dangerously Genre Savvy: When he sees the "Pizza Delivery Boy" (actually Francis and the gang) at his door, he immediately arms himself with a pistol, realizing that the person was not likely to be a pizza delivery person as he doesn't remember ever ordering a pizza that day.
Fat Bastard: Very large, very intimidating, and very much a despicable excuse for a human being.
Villainous Breakdown: While he's mainly calm throughout the movie, in the climactic car chase, he pulls down the gear stick so hard it breaks off and punches his hand through his car's window to get at Jenny.
Vile Villain, Saccharine Show: Especially for Disney. Sykes has no sorcery, hamminess or even a Villain Song; he is a cold-blooded Loan Shark played straight. His methods are brutal as he holds Jenny for ransom, has Fagin in a loan deal with the implications of mafia execution and, in one scene where he's on the phone, he's clearly instructing the person on the other end how to perform the Cement Shoes method.
Younger Than They Look: She appears to have only eight candles on her birthday cake. At the end of the film, no less. However, some have argued that she looks older than eight or seven. Jenny's voice actress (the same girl who starred in the star-studded Alice in Wonderland TV Movie in 1985) was about 12 years of age, when she voiced Jenny.
Anti-Hero: She is extremely jealous of Oliver when Jenny first gets him, and tries to get rid of him after that. Despite this, she does help Oliver and the gang rescue Jenny from Sykes's clutches and appears to have...slightly lightened up by the end.
Shrine to Self: Her room is not only stuffed with photographs and paintings of her and many, MANY mirrors, but statues of her make up most of her bed, flank her vanity table, and her dog bowl has a few miniature Georgettes on it.