In Multima every Pet can be upgraded and levelled exactly like any other character, there are different types of tamable Pets, more or less strong and more or less difficult.
Once you have tamed your Pet, it will be necessary to use Animal Lore (.useanimallore) on them in order to access the management menu which will appear as follows:
Exactly how you experience a new character, it will be the same with your Pet, so taking him to the Newbie Dungeon or graveyards where there are low-level monsters will be a good place to start. Whenever your Pet kills a monster you will notice a system message informing you of how much XP your pet is receiving.
What happens when your Pet passes a level:
There are a total of 250 Evolution Levels to overcome, remember that once the creature is tamed, its level, strength, HPs and damages will be reduced to 1/3 of its original value. So the higher level is when you tame it, the higher the potential that expands it can reach.
The Pet System it's only PvM.