You grab a creature within range by one of its limbs and attempt to transport the bones from that limb to the container used as a component. Make a melee spell attack. If you succeed, the bones from the chosen limb are transported into the container, and the creature suffers the effects of such a loss as detailed below. The bones remain inside the container until the spell ends. If you maintain concentration on the spell for the entire duration, the effect becomes permanent.

Arm(s) or Tail(s). The target creature cannot hold items, provide material or somatic components for spell, or make any attack, skill check, or saving throw using an affected arm or tail.

Leg(s). The target creature's base walking speed is reduced by the the same portion as legs removed. For example, a creature with 4 legs and a 40 foot walking speed would have its speed reduced by 10 feet. If the target creature only has one leg remaining, it cannot Dash and has disadvantage on any attempt to maintain balance. If it has no functional legs remaining, it falls prone and can only move by taking an action to pull itself up to 5 feet using any functional limbs it still has; additionally, it automatically fails any Dexterity saving throw, and any attack that hits the creature is a critical hit if the target is within 5 feet of the creature.

Head(s). The target creature loses the ability to use any attacks or abilities involving its head, such as a dragon's breath weapon. Additionally, the critical hits against the target deal double damage and ignore any nonmagical resistance or immunity. If a critical hit reduces the target to 0 hit points, it is killed outright.

When a creature made entirely out of bones - such as a skeleton - is affected by this spell, it instead takes 5d8 necrotic damage, ignoring resistance and immunity.
Creatures that lack bones, such as gelatinous cubes, cannot be affected by this spell.
If a creature acquires the container holding the target's bones, it can spend one hour to make a Medicine check against your spell save DC, restoring one limb on a success.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, you can attempt to remove one additional limb with a separate attack roll for every 2 slot levels above 3rd.

"What in the Nine Hells happened to my arm?!" - Wizzo shortly after discovering this spell