Here’s a brand new Unique that’s (presumably) been in the game since launch! A group of players discovered the 
Ring of Misfortune (and Well-Wisher title), obtained through some very specific secret interactions. While the ring isn’t exactly very useful, it may be related to the as-of-yet-undiscovered secret Cow Level!
Sowhatsthecatch shared the story on the Diablo 4 reddit, which was originally shared on the Not a Cow Level Discord. Sowhatsthecatch also shouted out Discord users Jimpen, Tweaked, Teire and Raffi1337m who either found elements out or shared them.
The culmination of a year’s worth of work by many people, we see the results in the video below. Nova_sgx and their group went through a pretty specific process. The new and not very useful Unique, as well as the Well-Wisher title, are the reward from the secret Lucky Coin quest. To complete it, one player of each class has to throw a Lucky Coin into the Scosglen well. Getting the Lucky Coin is tricky, as you have to use a greed shrine close to a mini-event where a solider gets killed and then creates a lootable corpse. That corpse then gives the coin. Once 5 coins are gathered, you can see what happens below.
Whether this all-round-13 ring has anything to do with the Cow Level or anything else is still up in the air, but it’s really cool even it it doesn’t. Interactions like these are always very cool to find in games, especially this long after their launch!