Lucifer

Lucifer is Lady Tremaine's cat and one of the sidekicks imprisoned in the Isle of the Lost. He is now the father of a few kittens and one of them is named Beelzebub, who was originally Carlos's pet cat. He is also known as Dragon Hall's animal mascot.

Before the Isle of The Lost
Lucifer is the Tremaines's pet cat. He has black fur and is depicted as a sneaky, wolfishly-wicked, manipulative, and cheating mouse consumer. In a particularly manipulatively conniving scene at the beginning of the original film, Lucifer tries to rid the château's pet dog, Bruno, outside of the kitchen by scratching him painfully and sneakily while Cinderella's back is turned. Bruno then growls loud and threateningly out of furious anger and pain, and Lucifer lets out a benign and exaggerated fake shriek of pain as if Bruno bit him. Cinderella hears Lucifer's whining fake screech and blames Bruno, bitterly scolding him to go outside and stop causing trouble. Back inside the kitchen, Lucifer wears a wide grin of wicked satisfaction but is also scolded by Cinderella for not getting along better with Bruno. He then lazily drinks from the milk bowl Cinderella left him while frowning sourly, until Jaq causes a distraction to lure him away from the other mice, in order to create a path to getting their breakfast. While returning with the mice, Gus struggles with carrying his load and easily grabs Lucifer's attention. Fortunately, and unexpectedly, Cinderella enters the room and accidentally takes Gus away on her breakfast trays for Lady Tremaine and her daughters. Lucifer manages to grab him again, but Cinderella later forces him to let Gus go.

When Cinderella is later sent to her stepmother's bedroom after being accused of putting mice into the breakfast trays, Lucifer joins his mistress and takes great pleasure in hearing the punishments Lady Tremaine places on her stepdaughter. However, his pleasure turns to dismay when Lady Tremaine tells Cinderella to give him a bath, which suggests that he doesn't like baths or prefers to remain filthy.

Later, while Lady Tremaine and her daughters are practicing their music lesson, Lucifer cannot stand Drizella's off-key singing of "Sing, Sweet Nightingale" and rushes out of the room to see Cinderella singing along while scrubbing the floors of the château's entrance hall. He decides to torment Cinderella by jumping all around the freshly-scrubbed floor with his dust-covered paws, ruining Cinderella's hard work. Noticing the mess Lucifer made, Cinderella intends to 'teach him a lesson' with her broomstick but is distracted by a knock on the door, which is the Herald delivering an invitation to the Ball at the Palace.

A while later, Jaq and Gus plan to grab a sash and a bead necklace from the laundry pile, since this is what the other mice needed in order to finish making Cinderella's dress for the ball. It was just their luck that Lucifer was also in the room, sleeping. Jaq and Gus try to quietly retrieve the sash without waking him up but to no avail. Fortunately, Lucifer, now wide awake, couldn't get a good grip on the sash, and the mice manage to get away with it. Now Jaq and Gus plan to take the bead necklace. Unfortunately, Gus blows their cover by yelling excitedly about the beads. Lucifer immediately sits on them and waits for the mice to make their next move. Jaq formulates a plan and starts off for Lucifer. Lucifer readies his paws and accidentally lets Jaq sneak behind him. Jaq, now amidst the laundry pile at the other side of the room, creates a distraction in the hopes of luring Lucifer away from the beads, giving Gus time to grab them and escape. Lucifer figures this out and uses his tail to keep the beads close to him as he moves towards Jaq. Once he gets close enough, Lucifer pounces on Jaq and chases him into the heap of laundry, mainly into a light-blue nightgown.

When the coast is clear, Gus made his move to get the beads. Once Gus gets them, he heads back to the mouse hole he and Jaq came in from but unfortunately slips on a bead and slams into the far side wall, briefly getting Lucifer's attention. Jaq immediately intervenes and gets him to chase him into the dress again. This time, Jaq makes an escape out of a sleeve of the dress with Lucifer close behind. Lucifer could only manage to poke his head out of the sleeve. Enraged by the trap he has been put in, Lucifer slithers across the floor aiming for Gus, now picking up the beads with Jaq. Gus barely manages to grab the last bead before Lucifer attempted to bite on him and escapes, leaving Lucifer temporarily trapped in the dress.

That night, Lucifer makes another attempt to catch Gus by trapping him under a bowl, only for the Fairy Godmother to turn Gus into a horse. The newly transformed Gus then whinnies loudly at Lucifer, scaring the cat so much that he runs off.

The next day, Lucifer attempts to catch Jaq and Gus, who has arrived with a key they have stolen from Lady Tremaine, while they try to free Cinderella from her locked room. He succeeds in trapping Gus, who has the key, beneath a bowl, and fights back at the mice and the birds who attack him. However, Cinderella's pet dog, Bruno, a friend of the mice and enemy to Lucifer, having been summoned by the birds on Cinderella's orders, intervenes and scares Lucifer so much, he sails out of the tower's window and falls to the ground far below, but survives as cats land on their feet.

The Isle of the Lost
Lucifer is one of the villains imprisoned on the Isle of the Lost. He has had numerous litters of kittens and one of them is owned by Carlos De Vil, whom he named Beelzebub. He is also the mascot of Dragon Hall.

Trivia

 * His name, Lucifer, is one of the names for the devil.
 * A painting of him can be seen in the Curl Up & Dye hair salon.