Got inspired by “Arrival” - an interesting Sci-Fi movie. I designed something like the alien ship, but with a bit more practical use for the regular user - a watering can that looks like that ship or like an alien seed. Please insert it first well in the substrate, then fill it almost 0,5l of water.

3D printing to keep water - not always easy. Use the maximum temperature for your material. Print the model, use some very fine sand paper to clean out the minor imperfections, apply some silicon grease or any technical grease/oil you might have to recover the faded colors.

Seal the exits, test it for water tightness - if leaking spray on it a few layers of clear lack.