Transmog

Transmog lets an item look like a different one. Your stats come from what you are wearing; the look can come from anything you have collected.

Who	Warpweaver
Where	Beside the auctioneers in every capital: Stormwind, Ironforge, Darnassus, the Exodar, Orgrimmar, Undercity, Thunder Bluff and Silvermoon.
Cost	The vendor price of the item whose look you are taking, and never less than 1 gold a slot. Hiding a slot is free.

How you collect a look

Every green, blue, purple and heirloom item you equip adds its appearance to your collection. Grey, white and legendary items do not count. Once a look is in your collection you can sell or bin the item itself.

To keep a look without wearing the item, type .transmog claim and then shift-click the item into chat. Claiming binds the item to you. .transmog claim all claims every new look in your bags at once, and binds every one of those items too, so take out anything you meant to sell or trade first.

The rules

A look has to fit the slot the way the game would let you wear it. Plate goes on plate and cloth on cloth, a sword takes a sword's look, and a two-handed weapon takes another two-hander. You also have to be able to use the item the look came from, so a tier piece locked to one class stays with that class.

A raid drop you can still trade to your group is not collected while you wear it. Once the trade timer runs out, equip it again or claim it.

You can save up to ten complete outfits as sets and switch between them at the Warpweaver.