Concept art of the baby bomb pet from Final Fantasy XIV.
Pets are a common feature in massive multiplayer online role playing games and refers to companion creatures that follow the player character that may either be a purely aesthetic feature with no direct impact on gameplay, or creatures that can be used in battle by certain classes. Non-battle pets are sometimes called "vanity pets" to distinguish them from battle pets.
The Beastmaster, Summoner, and Puppetmaster jobs from Final Fantasy XI, as well as the Arcanist class and it's Summoner and Scholar jobstones from Final Fantasy XIV are considered pet classes, relying on summoning monsters or taking control of monsters to battle. Dragoon job in Final Fantasy XI can also summon a Wyvern pet to aid in battles. Technically, the Luopan that Geomancers can conjure with Geo-spells also counts as a pet, although it radiates an aura instead of attacking directly. The canceled Necromancer that was planned for the Treasures of Aht Urhgan expansion also would have been a pet job that used undead pets.
While Final Fantasy XI does not feature "vanity" pets, Final Fantasy XIV has several "minions" that can follow the player around regardless of class, such as 'baby' versions of several creatures, ranging from chocobos to behemoths.