I purchased the Pearlescent Goblin Wave Shredder on the trading post today and it was not added to my mount collection. I have logged out for an extended amount of time, I have reloaded UI, I have turned off all addons, I have checked other characters. Nothing has worked and the mount is still not showing up, despite being purchased.
EDIT: Fixed. I am a fool.
Make sure you clear any filters, too!
oops
Did you know this mount can’t be used underwater? Fairly certain this is the only mount unable to do so.
Red Flying Disk can’t either, from my personal experience. Dismounts you if you go underwater on it, and can’t mount on it if already underwater.
after 4 days i have been doing everything the ticket told me to do, i saw the Sources button, clicked uncheck all, and then hit check all. and there it was… wtf =_=
Same. I bought it too and I did not get it. When I open trading post its not even showing in the list if items so I can’t return it. I was deducted the tokens for it.
I still don’t have the Amber Skitterfly I bought last month if that makes any difference. Same deal, it disappeared from trading post list so couldn’t return. Neither mount is in my mount journal at all.
Out a lot of tokens for the 2 mounts and nothing at all to show for it. 
Did you check to see if your trading post filter is checked in the mount journal?
OMG ty soooo much!! Yes I had everything checked off - collected, not collected, flying ground all that. Never even knew they added a trading post option! Thank you, thank you, thank you!
np lol, that was my problem as well. no clue the option existed