Pets and minions are a fairly common feature in several MMORPGs, but in MapleStory M they are a bit more interesting. Not only do they follow you around and act all cute, they also serve different functions in conflict such as utilizing your potions for Maple Mobile Mesos you if your health gets low or picking up items.
If you ever played with Castle Crashers, then they're a little bit much like that. You can equip them by heading to your character display, and then tapping Pets. From this menu you can see all the ones you've got available for you and swap them in/out to get a max of three. You can even feed them to level up them with Pet Food which lets them supply extra fans to you while researching the world of MapleStory M.
To get new and unique types, complete quests and some of them might contain pets as a reward. Free daily rewards may also feature pets. Finally, you can also buy Maplestory M Mesos utilize real-life money to purchase optional ones out of MapleStory M's cash store. From what we could see, these ones out of the store do not appear to be any more/or less successful compared to the standard ones you may get, not at par 1. They are just cute, and are distinct from the ones that you usually would find.
That does it for how to get pets and what they do in MapleStory M. Hopefully you'll encounter lots of cute ones you like as you play MapleStory M on your phone or tablet.