The DRUNKEN STARFISH watering hole.

Print with 4 top layers, 4 bottom layers and 2 outer walls. Around 25% fill recommended.
Print in ABS and vapour smooth to waterproof.
Recommend 2 x normal nozzle diameter setting for faster print.

The watering hole or oasis is a distorted semi spherical cavity designed to contain the water while being drunk from. Better for smaller pets.
Don't scale any dimensions, you'll upset the bottle screw socket connection.

Oh... Rinse out your fizzy/pop drink bottle, fill with clean water, screw this on the top of the bottle and invert it. Book mark here and post a pic of your pet drinking from it!

If you didn't download the current file "drunken_starfish_bestest.stl" then you may need to fill in a thin bit at the top of the square channel that doesn't print in thicker nozzle sizes. I repositioned and fixed in this file, also I lifted the base by almost 10mm and recompiled to drop a lot of weight and filament out of the model. :-)