Recently I have wondered how few items one could defeat the game's "final" boss, the enderdragon, with. Without armor and a weapon is certainly a hard challenge, but what if you had no water bucket, snowballs, food...
What if you beat the enderdragon with nothing?
After quite a bit of testing and trial runs, I have managed to do just that in Hard Mode. The only slight variation from the "no items" rule is that chorus fruit may be planted around the dragon's island to avoid starvation. However, you will still begin with an empty inventory, and the fruit must be harvested manually. In case you're confused - items ARE allowed to be used, but you cannot bring anything to the fight that wouldn't normally be found on the main end island (aside from chorus fruit). That means enderpearls from slain endermen are allowed, and THAT is how this challenge is made possible, albeit difficult.
On the only successful attempt I had, my time was roughly 3 hours and 20 minutes, having died a total of 19 times. I will leave the rules below for anyone who wants to try this.
Must be in Hard Mode.
Must not have ANYTHING in your inventory at the start.
May plant chorus fruits around the island. This allows you to eat and not starve.
Must NOT use chorus fruit as blocks (no using the plants to help kill enderman, climbing up plants, etc).
May die, although the fewer deaths, the better.
Must record a video while doing the challenge (no splices) to ensure that rules are being followed.
Must use playing 1.12.2 vanilla.
Must use a random seed.
I recorded myself doing this challenge and uploaded two videos of it. One is the full version (over 3 hours),
and one is the edited version.
Best of luck if you decide to try this out yourself. It was a blast to complete!