I don't mean what you use to chop down your feces, but an object that you realized only your family has and people would raise their eyebrows at. Best if said object has a sole purpose.
Probably have a ton of unusual/unique items, being a magician and juggler, but the one that comes to mind is our dedicated BBQ bellows.
This is simply an old re-purposed balloon pump and lives outside next to the fireplace. Best way to get the fire going, portable, cheap.. Beats blowing with your mouth/waving newspaper hands down.
I have grill bellows as well! Also, for camping I got a "pocket bellows" which is basically a collapsible tube you blow in to get the fire going. Handy stuff!