A pair of simple, unmarked crochet hooks. Closer inspection reveals them to be made of human bone. They are powerfully enchanted, but function only as regular crochet hooks.
If provided with materials, namely yarn, and asked nicely, the hooks will animate, and create a yarn item of legendary quality.
However, the will that inhabits the hooks seems to be either confused, or actively spiteful, and will never make the request correctly.
If the user asks for a sweater resistant to heat, they might get a heat resistant sock. If they ask for a scarf of water breathing, they might get a scarf of water walking.
The hooks will only work when provided with yarn, but work with incredible speed, production takes roughly an hour. The hooks will refuse to produce anything larger than a onesie. Once used, they cannot be used again until they are touched by the light of a full moon.