http://www.curse.com/downloads/details/3538/Basically, if you have a pet, or if you RP with someone who does, Pet emote is a good thing. What this does is it allows a Hunter or Warlock to /emote for their pet, so that the pet's name shows up at the front of the emote instead of their name. Example:
I type:
/pet screeches and dives at a rabbit.
People with Pet Emote see:
Pitter screeches and dives at a rabbit.
People without Pet Emote will see:
Willimeena's Spider Pitter screeches and dives at a rabbit.
Pet emote also makes occasional random /emotes for the pet that indicate whether it's happy or hungry. Folks who've travelled to a dungeon with me recently may have noticed Pitter "sizzling happily," etc. Sadly there aren't any random emotes for the Warlock's Demon yet, but Warlocks can use the /pet command to /emote for their companions just as Hunters can.
As far as I know, it does not work for temporarily summoned pets like the Mage's water elemental. But even if you aren't a Warlock or Hunter, I recommend it because it doesn't even show up as an addon taking up memory in WoW, and it just adds a little something extra to RP.