After his transformation into the Vampire Cat, his personality changed. Originally quiet, Mr. Whiskers was now loud and dangerous. He didn't listen to Weird Girl anymore, and hissed at her, though he never attacked her as he did with everyone else, hinting he has some memories of her. Mr. Whiskers appeared to specifically attack dogs now, and was no longer afraid of Sparky and tried to kill him. He seemed to take joy in scaring people, slowly crawling after Elsa and Persephone, and was very quick and fast. He would attack suddenly and unexpectedly, and was rather impulsive, quickly attacking Victor. His hatred of dogs would be his downfall, however, as he attacked Sparky rather than escape the burning windmill, which collapsed and killed both him and Sparky.
Vampire Cat flew to the science fair where the other monsters had been destroyed. As Weird Girl called to him, Vampire Cat flew towards Elsa's dog Persephone and grabbed onto her and flew away with her in his grasp. Both Elsa and Victor chased after them while Sparky ran away to get the angry mob, who chased after him, thinking he took Elsa. Elsewhere, Vampire Cat had taken Persephone to the windmill and Elsa followed and grabbed Persephone. Elsa climbed up the stairs while Vampire Cat crawled up after her, and flew up and hit her in the head, causing her and Persephone to fall and were hanging form the edge of the windmill. When Victor came to help, Vampire Cat knocked him down and started to attack him, but Sparky bit his arm. The cat flew up with Sparky and freed himself, and the two animals fought each other.
Elsa and Persephone fell and grabbed a rope, and swung to safety. With them rescued, Victor turned his attention to Vampire Cat and Sparky, who were fighting on the top of the windmill, and Sparky nearly fell off while Vampire Cat flew in the air and tried to grab him. Sparky slid to Victor and Vampire Cat tackled Victor and the two tumbled into the windmill, which had been set on fire. Sparky ran down and found the two, both unconscious. Sparky dragged Victor outside and left Vampire Cat. As everyone cheered that Sparky saved Victor, Vampire Cat recovered and flew out of the windmill, grabbing Sparky by the tail and dragging him back inside to continue their battle. Though Sparky attempted to defend himself, Vampire Cat quickly gained the upper hand and cornered Sparky against a wall. However, as Vampire Cat prepared to attack, a wooden stake became dislodged from the ceiling and plummeted towards Vampire Cat, impaling him through the chest. Giving a shriek of agony, Vampire Cat finally died of his injuries just as the flaming windmill gave away and collapsed on both him and Sparky, killing him too.
- Since the other monsters are meant to bare a resemblance to the original Universal Movie monsters, the Vampire Cat is meant to represent Count Dracula from Dracula.
- Sparky and the Vampire Cat's final confrontation at the end may represent the heated rivalry of Boris Karloff and Bela Lugosi, as well as the heavily thought upon concept of Dracula VS. Frankenstein.
- Unlike the other monsters, the Vampire Cat was not resurrected from a dead animal. Like the Sea Creatures, the Vampire Cat was mutated with the use of lightning and (in the Vampire Cat's case) a cat in contact with a dead bat.
- The Vampire Cat kidnapping Elsa may draw parallel to Winona Ryder's portrayal of Mina Harker in Bram Stoker's Dracula .
- He was the one who broke Mr Burgermeister's flamingo.
- He is the last animal to die in the film.
- Like many of the other animals/creatures in the film, the Vampire Cat is voiced by Dee Bradley Baker.
- Due to Mr. Whisker's almost complete mindless nature, The Vampire Bat easily took over him as if it found a new body.
- In the final confrontation the Vampire Cat is impaled through the chest with a wooden stick. The most well known method of killing a vampire was by driving a wooden stake through it's heart.
- The Vampire Cat resembles a mammoth-hunting predator,the Sabretooth cat (Smilodon fatalis).
- The Vampire Cat transformation is the same as the transformation in An American Werewolf In London 1981.
- The Vampire Cat fell down to the bottom of the windmill with Victor after it pushed him off a platform, starting Victor's rescue.
- Mr Whiskers form to Vampire Cat is reference to Stephen King's Cujo. How the bat's bite turned Cujo mad, the bat that Mr Whiskers turned him into a vampire.