What hunting weapon is designed to return to its owner?

It's the boomerang.
Notably not from Australia, but widely used in several cultures from all over the world and as early as the paleolithic: the oldest specimen was found in Poland and is dated around 23000 BC.

The question is partly incorrect. The returning boomerang is considered to be a toy or plaything while the non-returning type is considered a weapon.

Essentially, there are two types of this ancient Aboriginal device: the returning boomerang, and the non-returning. The former (designed to return to the thrower) was often used as a plaything - in tournaments and by hunters to imitate the sound of birds to drive them from trees; coastal Aboriginal communities favoured these lighter tools. The non-returning boomerang, however, was designed as a weapon, to be thrown straight. It's longer, straighter and heavier than its returning variety, and traditionally used by inland and desert Indigenous communities.

https://www.discoveraboriginalexperiences.com/article/guide-to-the-boomerang-in-aboriginal-cultures

So, neither poster answered the question. I posit, from my experience as a scuba diver, that the answer is a harpoon with a retrieval line.

Unlike a projectile you throw away and hope to find later, like the aforementioned hunting boomerang, a traditional hunting harpoon relies on a mechanical tether. It is designed to maximize the hunter's chances of recovery. When the harpoon strikes an animal (like a seal, whale, or large fish), the sharp point detaches from the heavy wooden shaft. The head is securely tied to a long, braided line made of sinew, leather, or rope held firmly by the hunter.

When the animal is struck, the hunter pulls the line to reel the prey back in. If the hunter misses entirely, they simply haul the line back to recover the more valuable weapon-head immediately without losing it to deep water or a current. A shaft is a dime a dozen; the head is attached to your next meal... if you're a decent hunter.

I don't believe that the Harpoon would be correct, the harpoon doesn't return, it's retrieved / recovered either by reeling it in or by swimming and picking it up, the object in question is "designed to return" which means the object returns to who or where it was launched.

Thinking a bit outside the box...
How about a hunting bird (Falcon or Hawk)...

https://www.britannica.com/sports/falconry

Hey elburcher,

Ok, then how about the General Atomics MQ-9 Reaper? Unarguably a "hunting weapon designed to return to its owner".

J

I gotta admit that I had the boomerang in mind when the question was written. However, some interesting answers have surfaced.