Someone on reddit wanted a toy for their daughter that she could hammer together, so I whipped this up for him. Link to thread:
The headboard of the bed is hammered into the body with pegs, then the footboard. The headboard has a hole that the top can go into, there's only one right now (Headboard Heart.stl) but I might make more.
You need 2 of each peg.
NOTE: I've just printed this, and am going to update the pegs very soon for a better fit!