The Dragon and Helmets question

[Neverlasting Fear]

Did pretty much everything else in the game full eremite armor, but I'm just wondering if the meme is there is no helmets or I genuinely missed them? I almost missed the healing spell ring inside of the Abandoned Mines because it blended in with the textures and came back later and accidentally found it.
For the dragon, is there something to tell if it's actually taking damage? I've been casting tornado at it, and I have the moonlight greatsword and a few other weapons but I don't think it actually hits.
Also last question Do the snails drop a new weapon like how skeletons have a chance to drop the battleaxe? I'd be mad if I missed that completion rate

[Rhys1201]

The dragon just has an absurd amount of health. 8 casts of Geyser will kill it