The Relic variant of One Horn, Oldhorn is extremely resilient with 2.4 million health and 30,000 DPS when unbuffed. He slowly approaches the Cat Base with 4 movement speed.
When you first encounter this time-traveling terror, he's the only thing in the entire stage, making it easy to build an entire set dedicated to defeating him. Prof. Cat Jobs makes this enemy very easy by weakening his damage down to a mere 120 per hit. Thaumaturge Cat can do the same but only weakens to 50%. Because Oldhorn is so vulnerable to being Crowd-Controlled, you can slow or knock him back with cats like Gato Amigo, Dark Emperor Catdam or Ururun Cat. Rodeo Cat is another great Cat to use as Oldhorn's short range allows Rodeo Cats to be stacked, resulting in a perma-slow.
An ancient prophet who can see the future. On a journey to go to people who will have bad things happen to them and give them advice, but he never gets to tell them because the bad stuff has already happened by the time he arrives.