Created after Archer Mendeleev lost his arm in an ill-fated deal with a hag; the alchemist turned lemons into lemonade. Incorporating a multipurpose tool into it, Archer was able to transform the arm to suit his needs — becoming the toolkit he needed in that moment. Most of the time, the arm was configured as an alchemist kit.
This item replaces a lost limb- a hand, an arm, a foot, a leg, or a similar body part. While the prosthetic is attached, it functions identically to the part it replaces.
You can detach or reattach it as an action, and it can't be removed against your will. It detaches if you die.
This arm contains machinery that can transform into a variety of tools; as an action, you can touch the arm and transform it into any type of artisan's tool of your choice (see the "Equipment" chapter in the Player's Handbook for a list of artisan's tools). Whatever form the tool takes, you are proficient with it.
While attached, you gain a +1 bonus to the spell attack rolls and the saving throw DCs of your artificer spells.
As an action, you can focus on the arm to channel your creative forces. Choose a cantrip that you don't know from any class list. For 8 hours, you can cast that cantrip, and it counts as an artificer cantrip for you. Once this property is used, it can't be used again until the next dawn.
This item can be selected by an artificer as a valid item for the Replicate Item infusion.
Notes: Bonus: Spell Attacks, Bonus: Spell Save DC, artificer