The RUST Scarecrow, a player deployable decorative base element, is available for purchase from the in-game item store during the Halloween Event each year (or steam store thereafter).
While serving no discernable purpose, Scarecrows do an adequate job (especially in the dying light of the day) at scaring the absolute pants off the uninitiated RUST player.
They bare a striking resemblance to another player, especially when viewed at an angle.
Some players deploy them around their base to create potential distraction targets in the event of a raid. Others place them outside of their enemies’ bases as a symbolic warning. You can pick them up after deployment at the cost of a portion of the item’s durability.