Harvesting Hands

1st-Level Conjuration (Ritual)
Casting Time: 1 minute
Range: 10 feet
Components: SM (a sharp knife and a pair of gloves)
Duration: Varies

Target a dead creature within range that has a CR of 3 or less. This spell conjures an invisible pair of hands that harvest that creature for any useful materials as listed in their harvesting table. No ability check is required to harvest these materials, the hands automatically succeed in harvesting them, and then place them next to the creature's carcass. You still need to provide any requisite containers such as vials or bags, but the hands harvest all materials in half the time it would normally take. You may direct the hands to harvest certain materials first. Once all of a creature's useful materials have been harvested, the hands disappear.
At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the CR of the creature harvestable increases by 3 for each slot level above 1st.

Source: Hamund's Harvesting Handbook: Volume 2