Enderman block trading

It’s be interesting if you could trade blocks with enderman. Like if you throw a emerald block at them they’ll give you a few diamond blocks or something like that. Or enderman can spawn with random blocks sometimes and you can throw a random block, and they’d drop the one there carrying for the one you threw. There could also be somthing like you can’t trade with them unless you’re wearing a carved pumpkin on your head. And there could be a unique block/blocks you can only get from enderman. Just a neat idea to make enderman slightly more interesting