What is Synchro effect?
All pets, when hatched from eggs or captured in battle, learn a random Synchro effect from more than 35 existing ones. A Synchro is a type of passive ability that allows your pet to help you further in battles. There are five types of Synchro rarities: Common, Incommon, Rare and Epic. Larger rarities are more difficult to learn.
To view the Synchro learned by your pet, access the Pet Curral and select the desired pet:
Although it is not possible to improve a Synchro, you can change it to another random one by feeding your pet with a fruit known as Cherry Bombs, for sale in the Shop.