Hiya devs! I wanted to bring extra attention to a few technical issues pertaining specifically to Battle Pet Collecting in The War Within that have not yet been addressed since launch. There may be other issues but these are the ones that jump out to me:
#1: MISSING PET SOURCES:
There are three battle pets listed in the Pet Journal which have incomplete source listings. It is unclear whether this is an oversight in implementation and fixes will come to illuminate us, or they are not intended to be included at all, or there is some “secret” element to acquisition that players need to solve. The pets and their details are listed below - would love some dev feedback on this (or if unintended just go ahead and hide them from the journal so we can all stop trying to figure it out 
)!
Caustic Oozeling (NPC: 222348) | This pet shows its source as “Vendor: ______”, but with nothing indicated otherwise. Of note here, there does not appear to be a companion item associated with this NPC (used to learn the pet, typical for a vendor pet) according to Wowhead.
Illskitter (NPC: 222069) | This pet shows its source as “Drop: ______”, but with nothing indicated otherwise.
Kaheti Bull Worm (NPC: 222585) | This pet shows its source as “Vendor: ______”, but with nothing indicated otherwise. Similarly to the Caustic Oozeling pet mentioned above, it also doesn’t appear to have a companion item associated with it.
#2: MISSING COLLECTION ACHIEVEMENT:
Players who have managed to collect 1800 unique pets in The War Within are receiving the Mister Muskoxeles battle pet, along with the title “[Name], Knight of Feathersworth”, surprising (and delighting!) many devoted collectors - but oddly, no achievement popped up when the rewards came through.
These rewards were originally linked to the achievement, [Good Things Come in Small Packages] - which launched in Dragonflight for collecting 2000 unique pets - but the achievement was removed when players pointed out that it wasn’t actually possible to achieve, given the number of pets available at launch.
It seems like the reward requirements were updated to 1800 in the files, but the achievement wasn’t reimplemented. It would be great if we could get that achievement rolled in now that the rewards assigned to it have gone out. I’d like my extra 10 points tyvm 
#3: MORE CAGEABLE ACHIEVEMENT PETS:
In the 8/28/2024 hotfixes, the achievement-reward Waxwick was updated to no longer be cageable/tradeable, as is the norm for achievement pets (gg!). But there are two more battle pets that are set as achievement rewards, and at least in the recent data files, they are not showing the correct “NotTradeable” flag to prohibit them from being caged. Those two pets to check are:
Ruby-Eyed Stagshell for the achievement [A Champion’s Tour: The War Within]
Lil’ Bonechewer for the achievement Worm Theory
And a final lil’ quibbling note for the Ruby-Eyed Stagshell above: while the reward item for it is the [Purple Stagshell], the actual pet itself is called Ruby-Eyed Stagshell. Now, I understand that oftentimes this is entirely intentional, as in the recent case of Bean, who is learned by purchasing the vendor item [Freshly Webbed Kebab]. This makes at least a little sense and, in-fact, made me laugh when I saw it. But in other cases like with the aforementioned Stagshell and also the Rak-Ush Threadling pet, which is sold on the vendor under the item named [Baleclaw], it makes it very complicated be sure you’re buying what you actually want to buy/figure out where the pet actually comes from.
Thank you for reading through this rather wordy (but hopefully specific-enough!) list of pet collecting-related issues. I will keep an eye both here and in-game for feedback and/or updates! 
— EDITED TO ADD… —
A few more collection-related issues have been brought to my attention and I thought I’d add them below:
#4: INCONSISTENT PET QUANTITY ALLOWANCE:
Historically in WoW, players have been permitted to collect up to three copies of each battle pet on their account, with the exception of certain special pet sources where only one “Unique” copy of the pet is allowed. Examples of the exceptions are the trading post pets, in-game shop pets, achievement pets, and certain promotional pets like the collector’s edition pets or BlizzCon pets (
R.I.P. me for never getting a Murky! P.S. bring it back for the 20-year anniversary please​:pray:).
However in TWW, the pets appear to have inconsistent - I might even say slapdash - settings for quantity allowance. For example, some of the “treasure” pets in the new expac are capped at 1/1 pets allowed, while a few have the normal 3 copies/tradeability. Here is a list of pets that seem to go against the historical grain in this regard. For each of these, I suggest making them cap at the normal three pets max, and making them tradeable as well (which follows the historical settings for these type of pets):
Blightbud, rewarded from the Dislodged Blockage puzzle treasure in The Ringing Deeps. —SPECIAL NOTE:— Blightbud has two unique models available, which makes it maybe the only pet to have multiple models but only 1 copy allowed!!
Mind Slurp, rewarded from the Memory Cache treasure in Azj-Kahet.
Oop’lajax, rewarded from the Disturbed Soil treasure in Azj-Kahet.
Spinner, rewarded from the Trapped Trove treasure in The City of Threads.
Again, these are inconsistent. In contrast, other treasure pets in TWW are the standard 3/3 and cageable, like the Nightfarm Growthling (which also has multiple models), and Lil’ Moss Rosy. (Note: I’m leaving the Dalaran Sewer Turtle off my “problem list” because, while it is a unique & uncageable “treasure” reward pet - and appears to have multiple scarf color variations - I give this one a pass as it seems to be a special callback to Dalaran and the scarf colors randomly change when you resummon it.)
#5: NO META ACHIEVEMENT FOR FAMILY BATTLER:
(Mentioned in a reply below and elsewhere so thought I’d add it here as well…)
Going back all the way to the Argus patch in Legion, there have been “Family Battler”-style achievements (like Flying Battler of Khaz Algar, Undead Battler of Khaz Algar, etc.), and in every historical case of these, there is also a “meta” achievement for completing them all which rewards a battle pet, like Family Battler of the Dragon Isles, Family Fighter, etc.
As of now, the ONE exception to this achievement structure has met us in The War Within: there is no “Family Battler of Khaz Algar” meta achievement, and thus no pet reward for painstakingly completing all 10 of the family achievements. From the commentary I’ve seen (and my own opinion, of course), players would really love to see one implemented asap!
While it’d be most appropriate to have the reward be a unique model as opposed to a recolor - if that’s not an option in the interest of expediency, I’d suggest one of the models already available in the files - like either Anub’Rekyute, which has an amazing name, or maybe even Fuzzy, as you can’t have too many baby jumping spiders in the game as far as I’m concerned! And as far as the Uniqueness Quotient is concerned, make 'em special by giving them a fancy hat or other costumery or something!!! (Though in either of these cases I’d suggest updating the data to make the chosen pet unique & untradeable before implemented so I don’t need to add something ELSE to this long list haha sowwy 
) !
Thanks for reading these updates!