Secrets Discord server can be found here: https://discord.gg/wowsecrets
In addition to these discoveries, Developer Jeremy Feasel announced that a hotfix was applied to increase Uuna's drop rate from the The Many-Faced Devourer. Go save Uuna!
Patch 7.3.5 is live this week! It adds two new pets, PVP Pet Battle achievements and tabard reward, plus a continuation of Uuna's story. [source]
New Pets
There are two new pets that collectors can obtain. The first is a reward from an achievement that can only be earned toward the end of a relatively short quest chain, and the second is a drop from rare elites in the new max-level area in Silithus.
Mailemental
Players must first obtain the breadcrumb quest from a lootable BoP letter on the ground next to a mailbox in Dalaran (Broken Isles). The item begins the quest Lost Mail. The lootable object has respawn time of roughly 2-3 hours.
The quest chain will take players to a new area, the Postmaster's Office, as well as other zones on Azeroth. Check out Wowhead's full walk-through of the quests.
Toward the end of the quest chain a mini-game is unlocked where players must sort mail into tubes. Completing the achievement "Post Haste" will award the pet.
In addition to earning the Mailemental, players that complete this fun quest chain will also receive a Bind On Use quest item that can be traded to other players, allowing the quest to be passed on similar to sharing the Brawler's Guild invitations.
Silithid Mini-Tank
Three new rare elites appear in the updated max-level area, The Wound, in Silithus.
All three rare elites have a chance to drop the Silithid Mini-Tank. The pet is BoP but it can be caged.
We hope that getting this pet to drop won't be as difficult as pronouncing each rare's name!
New PVP Pet Battle Achievements
PVP Pet Battle connoisseurs rejoice — there are new PVP challenges with a new reward.
Similar to the Family Familiar and Family Fighter, players will need to win 10 queued PVP Pet Battle matches using teams of one pet-type. Doing this for each pet family will complete the Family Brawler achievement and award a Master Trainer's Tabard (pictured left).
Complete this new set of Pet Battle challenges and show off your Pet PVP prowess!
Uuna's Continued Story?
During Patch 7.3.5's testing phase, some interesting dialogue regarding the non-combat companion Uuna was datamined (*SPOILER* Warning).
Uuna's flavor text was changed from, "One of the many children thought lost in the battle for Argus, only to find themselves infused into an Ur'zul." to an interesting description that possibly foreshadows where the datamined dialogue will take place.
(New text) "Uuna was found bound to an Ur'zul, and was released into the Shadowlands, where she wandered in the utter darkness."
It's still unclear when or where players that have liberated Uuna from her Ur'zul prison will encounter this new dialogue, but it's speculated that a solo-scenario, similar to The Deaths of Chromie, might allow players to follow-up on the fate of this Draenei child's ghost.
In my honest opnion uuna should have had battle ability after her mini quest. reasons for this are shes defeated her fears gained a wand and crown . she actaully fought with said wand too . Totally wish she'd been upgraded to fighter/battle pet status since she did want to continue with our journey. Makes me sad.
Despite her lack of battle status, you can use the pet mirror to take on Uuna's appearance.
There is an interesting adventure you can go on with Uuna after you get her. I am just not sure how you trigger it. Yet.
Just looted the Silithid Mini-Tank...
@Jayshwa: Fixed, thanks for pointing that out!
Just a nitpick - Dalaran (Broken Shore) should read Dalaran (Broken Isles).