In WoW social situations, combat and non-combat pets alike usually just take up space looking pretty. Hunter and warlock pets have many actions they can perform to help fight an enemy, of course, and for a normal gamer there's no reason they would need to do anything more. But sometimes, as a roleplayer, if you pat your pet wolf on the head, you might expect it to look up at you with those adorable puppy eyes; or if someone else pats its head, you might expect it to bite their hand off. However, with the emote system as it is, we can only type out custom emotes with our own character's name at the beginning of the sentence, never the pet's.
There's a way around this problem, which is actually quite obvious once you think of it, yet roleplayers rarely use it, so far as I have seen. If you write the possessive apostrophe-S as the first part of your character's custom emote, you can make your pet seem to do something on its own: "Isabeau 's pet wolf growls and bares his teeth." It takes a little bit more typing, and it leaves a space between your characters name and the apostrophe-S (since that's built into the emote system), but effectively it lets you roleplay two entities at the same time. Hunters and warlocks can use the PetEmote addon to help make this a little more streamlined.
Our reader Ellyndia, for instance, roleplayed a very introverted character that normally would not introduce herself to others, but using such custom emotes, she could have her Jubling walk up and interact with people first to get conversations going. Pets can reflect what your character is thinking but not saying out loud (by hissing or purring perhaps), or they can do anything that such pets in real life might do. Special non-combat pets such as the Children's Week kids, the interactive Animatronics, or even the magical Mojo, could all be especially fun to animate a little now and then. Certainly this technique would become very annoying if overused, but in moderation it can add a extra spice of humor, entertainment and even a touch of realism into the game.