Geek Native has a prophecy generator and, to be fair, it’s one of very many out there.
There’s something fitting about the Doom Quest from momatoes, though. For a start, there’s that vanity URL doom.quest. That sets the scene and is easy to remember!

These portents of doom come in threes, and they fit well together. Here are some samples!
The dead come back for the final time.
The alphabet has turned to dust.
Dwarves uncover a sapphire containing the last truth of the world’s creation.
A secret portal opens within the city and leads to a well filled with children.
The Pampangueno labyrinth finally unlocks its entrance after decades of being sealed.
A restless sorcerer creates an evil clone for companionship.
An audacious thief steals the Kingdom of Creation.
Two secret lovers carve their names on the skull of a prophet; their lives now intertwined forever, for better or worse.
A horse is elected the bishop of a religion.
There’s also a reason why the designer momatoes is offering out omens of doom. That’s the ARC Kickstarter, which has smashed through its funding goal several times over and still has two weeks left to run.
In ARC, player characters fight against time to fend off the approaching doom.