King Slime Hat

I was taking a break from the game when this item was added in the 2nd version of the DragonQuest crossover event. I DID play during the first one and got all the achievements and items from the event. The way I understand it, they added the King Slime as an extra item in the 2nd event only. Is there any way to get that item at present time?

Not that I'm aware of. From what I recall, it was only buyable from an npc that has since been removed.