The Vial of the Sands is a mount item, which teaches you to transform into a  Sandstone Drake. The mount is learned from  Recipe: Vial of the Sands, which is only found in  Canopic Jars, gathered from  Archaeology.While in flight, you can carry another ally on your back like a vehicle.

(This list of requirements for the Vial of the Sands comes from Wowhead commenters)
This alchemy vial teaches your character to be able to morph into a Sandstone Drake  a fast mount capable of carrying one passenger.

You'll need 525 Alchemy and the Recipe is obtained through Archeology. It is contained in the Tol'Vir Common Artifact Canopic Jar.
You will need 450 Archeology to find Tol'Vir artifacts and they are in Uldum.

The easiest way to obtain Vial of the Sands is to buy it from the Auction House. If you're made of money (and if there's anybody selling it), then go right ahead. If you're not that lucky, a more sensible solution is to find an alchemist who has the recipe. Ask in the trade channel (and be sure to offer a juicy tip), and hopefully you'll find somebody with the recipe.

 The best thing about the Vial of the Sands is that you don't need to grind reputation to get it. You don't need to camp one area for hours on end waiting for a rare spawn to appear. You don't even need to farm the same monsters over and over hoping for a rare drop. Granted, if you want the recipe you'll have to do Archeology til your fingers bleed, but just to get the mount all you need to do is shell out a considerable amount of gold.

The Vial of the Sands is a rare item, craftable by alchemists, which will allow you to actually transform into a dragon. Even better, you'll be able to carry an ally on your back. What could be cooler? Here's our guide to Vial of the Sands  how to find it and how to get the mats together.

If Alchemy is one of your professions, you might want to cut out the middle-man and make the Vial of the Sands yourself. First of all, you'll need to find the recipe, which isn't easy. You'll need an Alchemy skill of 525 to learn it, but in order to even find the recipe you'll also need a high Archaeology skill. The recipe is bind-on-pickup, to you've no option but to grind for it.

Like most of the items craftable with Archeology, the Vial of the Sands recipe is a random acquisition. You'll only find it in a Canopic Jar, and even then it's a low chance of getting the recipe ¨C around 5-10% per jar. The Canopic Jar itself is a common artifact found from Tol'vir digsites. You'll need an Archaeology skill of 450 before you get access to the Tol'vir digsites (they're all in Uldum).

You can expect to craft quite a few Canopic Jars before you find the Vial of the Sands recipe. Remember, it's a random drop, so it could be 10 jars, it could be 1, it could be 100!

  If you're not an Alchemist, or Archeologist, and you don't want to grind/farm/bleed your way to it (who does?) you can still purchase a Vial of the Sands from an Alchemist with the recipe, outright. There is a significant cost in materials that are crafted with the Alchemy profession, as well as an additional significant cost from the two materials that can only be purchased from a Vendor in Uldum.