The fitting that the eyeball screws into is usually a standard pipe thread. Home Depot, Lowes, etc have a big assortment of PVC stuff. Pipe, adapters, Tees, 90's, 45's, and from these and a drill you can fashion almost any type of sprinkler. Only problem I see is with something rigid screwed into the return fitting you have to be careful you don't whack it and break something. Some kind of flexible connection would be better. The one I made wasn't screwed into the return fitting but hooked to another port out of the filter. It was something kids (and adults) could have fun with.
Al
Bookmarks