Legendary Drop In Un'goro Crater

It appears as if your User Interface is playing tricks on you, Wotif.

I show no such item in your inventory.

Q u o t e:
I guess my quest log is playing tricks too because it says i have to collect eight of them.

Your quest log is a part of your User Interface, Wotif. :)

I suggest disabling all of your add-ons to see if this "resolves" your display issue. If you continue to experiencing this, you may need to reset your User Interface. To do so, you will need to follow the below steps:

1) Log out of World of Warcraft to your desktop, thereby exiting the game completely.
2) Navigate to the World of Warcraft folder, which is often found in the Program Files directory (the default path is C:\Program Files\World of Warcraft).
3) Either rename (or delete) the WTF, Cache and Interface folders. (Note: If you do not wish to permanently lose any third-party addons you may have accrued, or macros you've written for your characters, you would be well-advised to merely rename the folders, rather than delete them entirely.)
4) Log back into the game by double-clicking WoW.exe, ensuring that you do not reinstall any addons before doing so.

Let me know if you have any further questions, my friend.