I’ve acquired the Zan-Tien Lasso the other day and still have it. I’m trying to discern whether or not this serpent spawns during Mantid invasions. I am noticing that the spawn points of the Great Worms from Beyond have changed.
I can’t really find any confirmation either way via wowhead or otherwise. Was hoping someone here would know.
Thank you. 
Generally 1-2 hrs. I personally joined a custom group and received it that way without even having to lasoo and everyone in the group got it. I also think it only spawns during a movie invasion. Good luck
And by movie I meant mogu because lol phone auto correct
I’d think that is the case as well since the lasso is obtained during that invasion (can it be obtained outside the invasion?). But I still have the lasso in my inventory which suggest to me there may still be a shot. Perhaps, the spawn just changes?
Gah, wish there were more answers out there about this.
Edit: Yeah, wowhead doesn’t seem to say the lasso can only be obtained during that Mogu assault. Hm…
Edit: okay, well I sat there for roughly ~40 minutes. I’ll report back if I have any luck later.
I am fairly certain both cloud serpents can only be obtained during Mogu invasions.
It seems it cannot spawn during this assault, according to this poster. I’ll just have to wait, I suppose. I’m crossing my fingers my lasso doesn’t disappear. 
I’ve had my lasso in my bags for a couple of weeks now.
Oh… is that what that thing is for? I had no idea. It’s been in my bags for a week or two.
Honestly when it’s a mogu invasion, just join a group (making sure it’s warmode on or off depending on what you’re going with) what happened in my group it was advertised as spawning very soon or something and I didn’t even use the lasoo. Someone used their target macro as it spawned (I never saw it lol) and everyone in the group received the dragon in their bag. Good luck!
That’s excellent information to know, thank you. I figured everyone had to capture their own serpent. We should see a Mogu invasion some time this week, correct?
I am not sure tbh but your lasoo will not disappear, it will stay in your bags til you use it. I had the lasoo since patch went live and missed the dragon when i camped on my own the first couple times because it flies super fast. But yeah when it is a mogu invasion best bet is to join a group and camp with them. Can make new friends and have good banter while you wait and someone will be spamming their macro and everyone should get the mount.
I’m from the Secret Finding Discord, and I can tell you that it only spawns during the Mogu invasion, and can take as long as 5 hours to respawn. The invasion will switch over in the middle of the week.
Please keep in mind that the Cloud Serpent is VERY SMALL.
He’s about the size of someone riding a serpent mount. He’s not Alani sized.
He’s also VERY quick.
These two things make him very easy to miss.
My Fiance got the Lasso and and just as we were headed back to Org, he noticed something zipping past us. Took us a second to realize that it was indeed the cloud serpent.
Once the first person captures the serpent, everyone else in the raid has 10 seconds before it despawns. Spam this macro when it spawns:
#showtooltip item:174927
/stopmacro [channeling:Catching]
/cleartarget
/tar Ivory Cloud Serpent
/use Zan-Tien Lasso
The Mogu invasion will be sometime next week.