I used a plastic lime, but if you can find some sot of larger plastic melon, that’d work as well. I got these at dollar store. Craft stores like Joanns, AC Moore and Michaels all have egg-shaped foam, actually! They’re a tad bit larger than mine, but I’d look for large plastic fruit like a melon, personally, because they’d be cheaper and more egg shaped. But that all depends on your convenience!