ok so a second unique skin has been discovered as tamable- the Ivory serpent. i will add a section for that one at the bottom of the post.
So as some of you already know, you can tame the thundering white serpents by using a special toy now. I recently got my War serpent and thought I would share what I learned. it is unclear as to whether this is something working as intended or something that will be fixed later on- so best to get one sooner rather than later. besides, it will be even harder to get once the xpack hits and everyone leaves bfa zones. these two skins are the only special skins this trick unlocks so far. (note that you can tame a few interesting ones, such as elusive quickhoof and a donkey skin that is otherwise tricky to get- but those have other models to tame from)
If you don't know what im talking about, these friendly War serpents are your target.

Now obviously, these guys are friendly to everyone. thats where the toy comes in. you need: N'lyeth, Sliver of N'Zoth ( https://www.wowhead.com/item=173951/nly ... r-of-nzoth ) it turns you hostile to everyone. So here is some important info on getting the blade!
Choosing a location.
first off, you will need to pick a location to do this in. There are some important things you should know before getting into this because location dose matter.
1: you may not need the toy to tame the serpents if you do this IN THE VALE. (note, it must be done in the invasion vision of the vale, not the past version.) the quest will give you a ONE TIME USE charge that will make you hostile. but if you mess it up, you have to start all over again. this method is not recomended.
2: if you get the quest for the dagger and then leave BFA content (or possibly if you hit a loading screen or you log out) it WILL REMOVE your ONE TIME USE buff and you cant get it back unless you start over. for this reason, i highly recommend just completing the quest for the toy instead of only going for the quest buff.
3: All of this pvp is going to eventually give you the "assasin" mark. this mark prevents you from using your flying mounts and marks you on the map to other players. you drop loot when you die so people will be looking for you. be ready.
because of all of these reasons, i recommend going for the toy in this location here. there are trivial crabs to stay in combat with and if you get attacked you can run into this cave and it should phase you away from your attacker.

getting the quest
1. there are lots of players in the "hunters pet" section of the secret finding discord that have been making groups for this. you might find help there.
2. Warmode MUST be turned on for any of this to work- including taming the serpent.
3: you gain the quest for this toy by killing ten enemy players. Honor kills are bugged right now, so you cant be in a group when you get the kill or it wont count. So on top of having to have an ally who can phase you to the same realm as the opposing faction volunteers, you need to juggle realms a bit. you will know that the kill counted if your chat says you received honor points.
4. since you cant get kills while in a group, it make this tricky to get cross realm help. you need to either tag your target, drop group, kill target & rejoin your group to stay on the same realm as your cross-faction helpers- or you need to anchor yourself to the realm by staying in combat with something that won't kill you. In the location recomended above, i would aggro a small crab and trap it to keep myself in combat after leaving the group. this usually worked.
5: if you die any any point in time, your kill count resets!
6: there is no cooldown for honor kills for the first part of this process. We had a healer rezzing our volunteers and we could immediately kill them again.
Getting the dagger
1: since this toy is account wide, you do not have to get it on your hunter. i recommend using whatever toon is most likely to survive a surprise attack.
2: if you die, log out, or leave BFA content (or possibly hit a loading screen? unconfirmed) the quest will be removed.
2: at this point you will probably be an assassin or close to becoming one. be ready to run.
3: you can only kill players of the same faction as you for the quest. no cross faction kills will count.
4: unlike with the cross faction kills, killing someone of your faction will give that player a 10 min debuff. killing them again while they still have this debuff will NOT count towards your quest.
5: the debuff will not drop when logged out. so have lots of alts ready and if not- you have a long wait ahead of you.
Rajani War Serpent Taming
the actual taming of the serpents is quite easy- just walk over to them, use the toy and tame away. i would recommend making sure no one is nearby when you do it though, since the buff is removed if you die and it has an hour cd. i would target them from the bottom of the small hill they are on to avoid enemy npcs.
(NEW!)
Ok, so it looks like people discovered how to tame the Ivory Cloud Serpent using the same trick as above. I did not think it could be reached, but i was wrong. this one is much, much harder to get, however. if you are on a server with a fair population you will need some help from a dead realm.
Ivory Serpent taming:
things of note:
1: Warmode MUST be ON
2: Sliver must be activated. (i recommend waiting until it spawns and is near the gate to use this to prevent ganking)
3: the serpent moves FAST. you need to run ahead of it as soon as it spawns and get in position. You can attack it once you use the toy, causing it to stop flying around and come to you if your trap misses
4: Still in testing but it looks like players can still lasso it for the mount and you can tame it before it despawns but you have to get the timing just right and everyone has to be willing to work with you.
5: while possible in theory, dismounting, using the sliver and then tagging the serpent on the way down so it follows you might work but it would be very, very hard to do since he moves so fast. best to wait until he flies over the gate.
So, here is how it works. The Ivory serpent is on a 2-3h spawn timer and it spawns waaayyyy up in the sky. This friendly npc will likely be camped on most servers since players can lasso it for a mount. If it gets lassoed it despawns in 10 seconds. If its not lassoed, it will continue to path up towards the big gate where you can land on the roof and tame it after using the sliver. This bugger is fast and flies in a loop so you need to camp his spawn point with a macro that lets you know when he appears, then you need to race to your taming location. In order to avoid pvpers with nets and the annoying worm debuff, you want to camp around this location at about this height. if you get the debuff, fly a little higher. it should be noted that he will be spawning below you if you are camping at this height, but he will still be quite a ways off the ground.

Here is the macro i used to search for him. i bound it to my mouse wheel and it would play a sound when it targeted him. since he is a friendly npc, silver dragon/npc scan don't usually detect him unless you add his ID- and even then you may have to mouse over him for detection. so get ready to spam the macro for a few hours.
/cleartarget
/tar Ivory Cloud Serpent
/cleartarget [dead]
/stopmacro [dead][noexists]
/tm 6
/run PlaySound(SOUNDKIT.RAID_WARNING)
once you see him, race to the location pictured below. note the map location, arrow direction and coords in this picture. you do not want to set your traps up on the wrong side of the gate or you will miss him. lay your trap along the spine of the roof, around where I am standing.

after landing here, use your toy and he will become neutral but will still be racing by at crazy speeds, so make sure you trap or shoot him, then tame away!
