Had this idea while playing The Binding of Isaac. The item "Best Friend" is a decoy that monsters attack and, after a few seconds, explodes. My idea is similar. You get a smoke bomb that you throw at the ground. While smoke fills up the air, a few doppelgangers spawn like in the screenshot below. Attacking them results in something bad spawning, whether it be a zombie, a primed tnt, a blindness splash potion, etc. You can use this item to flee while the enemy is shrouded in smoke or as an impromptu defensive mechanism. Lemme know what you think.