This is a puzzle in 5 pieces. It (dis)assembles with a screw movement.

And when it is assembled, you can "put the potty on the potty".

Tip:
when you have printed it and there is too much resistance to assemble it easily, try polishing the touching surfaces with sanding paper, until you cannot feel the different layers anymore.
That will certainly help.
The distance between the pieces is 0.10 mm.

Thanks to https://www.thingiverse.com/cerberus333 for his upload of the "Trump Balloon UK visit 2018".