A water cup is essential for washing little kids, add a little Magic (well science...) to the fun!
When the user fills the cup under the marked line it does not leak, but when you fill past that line it then starts to drain the whole cup through the bottom.
This is caused by the siphoning effect through a channel hidden in the mug.
The cup can be used as a bath toy because you can play with the toy in a wet environment where it doesn't matter how much water you spill. Its also functional for rinsing soap off the kids.
This model prints with no supports.