Pet Stash:
Gardo will also allow you to store additional pets by selecting Pet Stash. Open up this menu after speaking with him, and select the pets you wish to stow away. Battle of the Immortals will free up more room in your pet tab so that you may collect more pets without having to discard previously obtained pets. You can increase your Pet Stash size with the Pet Store License.

Pet Reincarnation:
All of the quests are performed at Ligg in Atlantis Square. To Start with Reincarnation: You will have the option to select Reincarnate Pet after speaking to Ligg. To Reincarnate your pet, you will have to select which pet you wish to reincarnate, insert the desired reincarnation item, and select "Reincarnate".

Reincarnating your pet does a number of things. The goal of reincarnating your pet is to raise its Quality, Mood, and base Growth Rate. Be warned though, if you reincarnate a pet multiple times, the Growth Rate may fluctuate and won't always result in a higher value. Also, it is important to note that your pet will be reduced back to level 1, and his Boost Level and Fortify level will be reset.
Pet Fortification:
 
Ligg will also allow you to fortify your pet. Fortifying your pet will increase your pet's combat stats. Select Fortify Pet while speaking to Ligg and the Fortification UI will appear. You will need to select the pet you wish to Fortify, and be in possession of a Pet Gem. After you have done this, simply select Fortify to complete the process. Be careful, different Fortify levels have variable chances of succeeding. Fortification levels range from level 0 - 15.

Pet Decomposition:
Lastly, Ligg will allow you to perform Pet Decomposition, also known as Pet Crystallization. Pet Decomposition/Crystallization is a way to turn a pet into valuable items used for Pet Boosting and Fortification. Speak with Ligg and select Decompose Pet. Select the pet you wish to crystallize and select "Crystallize".Higher Quality pets will yield higher quality items after the process is complete.