To claim a pet you will need to find the mob you want in the survival world and kill it with a lead in your hand. You must have a lead in your hand when you kill the mob or it will die instead of becoming your pet.
Players can have up to 3 pets in storage and 1 active pet at a time. To claim an additional pet you must first store your current pet with /petswitch store. Once you have stored your current pet you can simply kill another mob to make it your pet. You will not be able to call it or interact with your other pets while they are in storage. To interact with your MyPet you will need to make it your active MyPet by doing /petswitch and selecting the one you want to use.
Pets can be assigned to a skilltree with /pcst, which allows it to level up and unlock new skills. There are 8 skilltrees to choose from, but Mage, Tank, Marksman, and Warrior all require you to start with "Fighter". Pets earn XP when they kill mobs, and also earn a small amount of XP any time you kill a mob.
Note: pets with inventories will drop it on player death.
Some pets can hold items in their hands or wear armor. To equip a pet with something to hold or wear, simply right click on your pet while shifting with the item in your hand. To remove the equipment right click on your MyPet while shifting with shears in your hand.
You can change the way your pet attacks by changing its behavior. Different behaviors are unlocked as your pet levels up. The available behaviors are listed below.
You must feed your pet to keep its health up or it will die from hunger! If your pet is hungry it will also be weaker and will deal less damage when attacking.
Each pet has a special food that it must be fed. You can see which food is right for your pet by doing /petinfo.
There are two ways to disable a pet, and they work very differently. The first, /petsendaway, will hide your active MyPet until you un-hide it with /petcall. A pet that has been hidden is still considered your "active MyPet", it just isn't visible right now. It also only hides your pet during your current session, so your pet will reappear if you disconnect and reconnect to the server.
The second way to disable a pet is to put it into storage with /petstore. Pets that are in storage are completely deactivated until you use /petswitch to choose one you want to use. If all of your pets are in storage, the server will tell you that you do not have a MyPet. This is also how you can claim additional MyPets - by completely deactivating your current one first.
The following mobs are not allowed to be claimed as a pet: the enderdragon, villagers and villager-like mobs, shulkers, ghasts, and elder guardians. If you kill any of these mobs it will die and will NOT become your pet.