Ivy has two personalities: one is a cute, sweet, innocent girl; the other is an evil, deceptive, conniving girl.
Ivy De Vil pretends to be a sweet, kind, thoughtful and caring child (this even made the Dearly Family question how she could possibly be related to someone like Cruella by blood); though it doesn't take long for the Dearly Dalmatians to discover that her personality was just a ploy and that she exploits her kind persona in order to deceive those around her into believing she's purely innocent. Ivy tends to work for her relatives in order to help them achieve an objective, in which she uses her innocence as a means of getting past most people's suspicion; though Ivy also likes to use her innocent nature as a means of placing the blame for an action on somebody else, even if it doesn't seem logical that they could have been responsible for the transgression.
While Ivy is initially subservient to her relatives, she gradually becomes more and more dominant and it doesn't take long before she starts bossing Cruella around, though Ivy's appearances in the series are rather infrequent. In order to make her innocence seem more believing, Ivy tends to speak in a very soft and polite tone, though she also walks around with a toy stroller, along with various other toys; though the stroller and toys are actually highly advanced technological equipment that Ivy uses to send information to Cruella and vice-versa. Despite the fact that Roger and Anita believe she's one of the kindest people they know, the Dalmatians realize they'll have to work extra hard to prevent her from succeeding in her schemes.
- Whenever Ivy is nice, her pigtails are down, but whenever she is bad, her pigtails go up and almost resemble devil horns.
- In the episode "Coup DeVil", Ivy's change from good to bad is reflected by her clothing: her dress was blue when she was nice, but then turned red when she was bad. After this, her dress stayed either blue or red for the whole episode.
- Ivy is similar to Suzy Johnson, as she can be cute and innocent beside very mean as well.
- Ivy is also similar to Two-Face from Batman, as both have a two-sided personality - even symbolizing them with the color of their hair.
- Ivy is also similar to Minima De Spell, both being nieces of two great Disney female villains (Ivy of Cruella De Vil and Minima of Magica De Spell).
- Ivy can have been inspirated from the character Shreeky of the 1985 TV series Care Bears: both characters have somewhat similar physical appearance and personality being both nieces of two great villains as well.
- Ivy shares the same first name and hair color scheme as Princess Ivy, a character from Sofia the First: The Curse of Princess Ivy.
- Although Ivy is Cruella's niece, Cecil is not Ivy's father, meaning that both Cruella and Cecil must have another sibling - most likely a brother, in order for Ivy to have the surname De Vil.