So for some reason my trigger enjoys taking the plastic protective ring on the bottom of my powerhead off

literally pulls the koralia 4 off the glass away from the magnet then pulls the bottom round plastic part off to play with.
My Mom came over and saw this and told me that (and she was being serious) I need to get a plastic toy for my poor fish to play with

ya right I'm thinking. Then Doug makes a joke about getting him a kong toy
Of course now I'm sitting here (and I've fished the plastic ring out of the tank for the third time tonight) wondering if maybe they are right???!
The trigger has a piece of rock he usually plays with but it seems he's bored with it now, can't help but wonder if he would play with a kong, also not sure if a smaller kong would sink or float. Thoughts? Opinions? Ideas?