Grumpy Cat
The Grumpy Cat is an EXCLUSIVE pet that was briefly sold in the Exclusive Shop for 499 Roblux. It was released in the Tech Update. It is based on the Grumpy Cat meme.
The latest Pet Simulator X value list for Grumpy Cat can be found below:

Regular
💎 33,000,000,000 (33b)

Golden
💎 Not Available

Rainbow
💎 Not Available

Dark Matter
💎 Not Available