Here's a baby rattle I designed for my baby. It's in two pieces and with a hole in the ball so you don't have to pause the printer to add the beans. It's designed so that the handle fits into the ball tightly, but it's probably best to glue it anyway just in case.
I added STLs for a larger version. Besides for being scaled up, I adjusted the tolerances and the like.
The ball should be printed with rafts, and optionally supports. The handle should preferably have supports as well.
Pour some beans into the ball, then attach the handle to the ball and apply glue for extra strength.