Buy a pet in the mall and put it in the pet window of your backpack. Double-click the pet in the backpack and it will come out. When the pet is outside, double-click the picture of the pet in the backpack and it will return to the backpack.
The upgrade method of Adventure Island pets is as follows:
When the character communicates with the pet and feeds the pet, the intimacy of the pet will increase. When intimacy reaches a certain value, pets will be upgraded.
There is a pet park in Shooter Park in Shooter Village. There is a pet training ground there. After talking to the pet trainer, you can reach the top through all obstacles in the training ground to improve the intimacy of your pet. When the pet reaches the advanced level, it can talk to the character directly.