As soon as you complete his Giovanni's Workshop quest, Giovanni gives you this beauty. Fortunately, it has an element in common with Magnus' Genius of Giovanni quest, so if you can time them so that your Toy Sheep counts for both, so much the better! Also, don't sell off any leftover brass gears when you're done with this quest. If you have a helpful alliance that will trade items back and forth with you, they'll come in handy for later quests as well!
After you're done with this quest, you'll move along to the three-part A Hot Time quest, also given by Giovanni.