Panda Carrier Puzzle

I got this puzzle as a present and was surprised I didn't see the model here on Thingiverse. I checked but couldn't find any patent or license so assume I was free to make model and post it here. If anyone knows better, please let me know and I'll act accordingly.

Difficulty: ★★★★★ (whatever that means)

Print the piece 24 times and have fun! Freecad model included.