Sapphire Phoenix
The Sapphire Phoenix is an EXCLUSIVE pet that was on sale in the Exclusive Shop for 4,999 Robux. It was released in the Christmas Update. It is no longer available unless through trading. It is the first pet that is Exclusive and to have over 100 billion damage.
The latest Pet Simulator X value list for Sapphire Phoenix can be found below:

Regular
💎 52,000,000,000 (52b)

Golden
💎 Not Available

Rainbow
💎 Not Available

Dark Matter
💎 Not Available