Mature zucchinis can become gigantic. Like some pumpkins, they can thrive off of neglect.
The inner flesh or vegetable is still usable. You may have to slice the dark skin off first, but yes, it can still be cooked and digested. Just chop some onion, green bell peppers roasted chicken with the zucchini, maybe add some eggplant and sesame seed oil. Stir fry and serve hot.
I make soup out of the really big ones. Take off the tough skin, scoop out the seeds and dice into small cubes. I love zucchini and potato soup.
If you have chickens they would devour it just slice it in half.
About 10 years ago I planted some zucchini seed. Every single zucchini those bushes put out was huge. One was enough fried up for 4 people. No telling how big they would’ve got if I hadn’t picked and ate them.
I haven’t been able to find any seeds or plants like that since. I’ve looked.