Can be made through crafting or possibly by using a lumberwood figurine and is placeable indoors. You can put clothing/gear on the mannequin the same as you would your playing character. If you'd like to secure your mannequin you can make a "glass case" with nails and 4 glass panes. This case can be locked so that others can't steal the clothing you've placed on the mannequin.
More like if you wake up to your village having a brawl outside with some raiders you can quickly swap out into fighting gear and charge out with your halberd and steed.
dageir wrote:I guess, but you might as well have a wooden box.
Not exactly. Most mannequins work in that you click them to open their equipment window where you can drag items onto it to wear. There's then an "equip" option up top which will swap out whatever you're wearing onto the mannequin and equip you in the mannequin's clothing.