You can be an item frame

In gamemode 3, you can click an item frame or ender crystal, and become it

Step 1: Place an item frame or summon an ender crystal
Step 2: Type /gamemode 3
Step 3: Click on the item frame or ender crystal

You are now an item frame

Because this works, I would expect to be able to be a dropped item because it's an entity, but I can't do that