There's a bell at your doorstep. You went and opened it to check. But you only found a box on the ground, there's a letter attached to its front that says;

"Please Take Care Of Him." With no other context. You brought the box inside to examine it. You open it, only to be greeted by a small as your palm dark clothed humanoid creature. It hisses like a wild cat. "What are you looking at? Don't you dare look down on me." It has a surprisingly deep voice despite its size.