If it is about a water toy that he can play with that has flowing water, consider a Heron's fountain. https://en.wikipedia.org/wiki/Heron%27s_fountain https://

If it is about a water toy that he can play with that has flowing water, consider a Heron's fountain. https://en.wikipedia.org/wiki/Heron%27s_fountain https://en.wikipedia.org/wiki/Heron%27s_fountain There are many YouTube videos that show how to make one using low cost / household materials.