Haxolotl
The Haxolotl is a LEGENDARY pet that is available from the Hacker Egg found in the Tech World. The Dark Matter version of this pet does over 1 trillion damage.
The latest Pet Simulator X value list for Haxolotl can be found below:

Regular
💎 450,000 (450k)

Golden
💎 1,300,000 (1.3m)

Rainbow
💎 2,000,000 (2m)

Dark Matter
💎 6,300,000 (6.3m)