Pets

Pets are a mechanic that provides buffs to various parts of the game:
 * Economy (Applies multiplicative buffs to Quest Gold Acquisition, Quest Time, Quest Upgrade Cost and Unit Upgrade Cost)
 * Guild Wars
 * Guild Raids
 * Battle Arena
 * Stage Pushing

Unlocking Pets
A pet is unlocked through the acquisition of pet fragments: At level 1 and level 3 a buff is unlocked. At level 5 one of 3 things occurs: When a pet levels up the buffs are increased.
 * Level 1 - 10 Fragments
 * Level 2 - 20 Additional Fragments (Total 30)
 * Level 3 - 50 Additional Fragments (Total 80)
 * Level 4 - 100 Additional Fragments (Total 180)
 * Level 5 - 150 Additional Fragments (Total 330)
 * If the Pet has a "Hero Couple", the unit in question normally receives a buff to its fighting power and passive abilities.
 * A Legendary (7*) Artifact is unlocked.
 * If the Pet has neither a Legendary Artifact or a "Hero Couple", then it simply receives another buff. However, very few pets have neither.

Main and Revival Pet
Two pets can be chosen to be the Main Pet and the Revival Pet. The Main Pet has its 2 buffs strength double during normal game play, the Revival Pet has its buff doubled and applied when reviving.

Pets not selected will still provide their buffs constantly.

Pet Types
Hero Couple Pets

These pets are linked to one of the in game units. At 5* they provide significant buffs to that unit.

Seasonal Pets

Pets that are generally given in Mailbox Gifts (for free or through purchases) at certain times of the year. Often available in the Pet Shop as well.

Guild Raid Pets

These pets are acquired through defeating bosses in Guild Raids. Reaching 5* unlocks a 7* artifact.

Greek Pets

A group of 12 pets named after Greek Mythology. Reaching 5* unlocks a 7* artifact.

Secret Shop Pets

A group of 9 pets only available through the secret shop by trading in surplus frags.

Fragment Acqusition
Pet Fragments can be acquired through a few mechanics:
 * Spirit Highlands - Pets with a 5* Unit as a hero couple.
 * Outland Battle - Pets with 1* - 4* Units as a hero couple.
 * Mailbox Gifts - Random gifts from the developer and purchases through the main shop.
 * Guild Raid - Fragments earned through Guild Raids.
 * Pet Shop - Purchase most 5* Unit pets and Seasonal Pets for Gems, Guild Coins and Honor Coins. Purchase recent honor units pets and "Greek" pets for Raid Coins.
 * Secret Shop - Purchase recent honor units pets and a few other pets using surplus fragments of other pets.