Originally released as a preorder exclusive on Amazon in Japan, the Monkey Business Devil Breaker is probably the most functionally useless prosthetic combat arm you can equip in Devil May Cry 5. The arm is simply a bunch of bananas. It wobbles around and looks silly as you use it to punch demons in the face, but it's not exactly a tactical powerhouse.
While the arm isn't actually useful, it is fun, and now it's available for free to anyone who wants to download it.
The weapon cannot be purchased from Nico, but if you've downloaded the free DLC, you may find it lying around stages. It can't be used in Bloody Palace, but if you want to really take out that big bad in style, taking out his final piece of HP with a banana arm seems like a fairly good way to to show him who's boss.
The Monkey Business Devil Breaker is available to all players on PC, PS4, and Xbox One.