Claws!

 Claws! was the first book in the Goosebumps Hall Of Horrors book series. It was followed by Night of the Giant Everything.

The cover illustration featured a cat with claws.

Plot
Mickey Coe and Amanda Underwood are in charge of their vacationing neighbor's cat, Bella. All they have to do is make sure she has enough to eat and does not destroy the house. Seems simple enough. But Bella escapes from the house and is hit by a truck. Mickey feels awful. Amanda has an idea to replace the cat with a look-alike from the local pet store, Cat Heaven. They find a cat that looks exactly like Bella, but the clerk will not sell it to them. So they decide to steal it. Big mistake! These cats are more what they seem to be...

Trivia

 * Mickey's fish are named Nick, Kevin, and Joe. This is a reference to the Jonas Brothers.
 * Despite being considered connected to the Goosebumps HorrorLand series, this book restarts the numbering (it being one).
 * Interestingly, it describes itself as being Goosebumps HorrorLand: Hall of Horrors. This contrasts with all others in the series, which drop the "HorrorLand" to describe themselves simply as Goosebumps Hall of Horrors.
 * Elements from Cry of the Cat are used.
 * This was the first book to return to the anthology series after Goosebumps Horrorland.