Moon Slayer

Moon Slayer is a First Sea spawnable boss stationed on Boss Island, summoned through the island's dedicated summoner mechanic rather than appearing on a fixed timer. With 1.25 billion HP it sits well above the typical early-game encounter, demanding a solid build before your first attempt. Because it is spawnable — not on a world schedule — you can control when you fight, making it one of the more accessible mid-tier bosses for players farming on their own terms.

The drop table is notably generous at the top end. Every kill guarantees a Race Reroll and a Boss Ticket, and there is an 80% chance of a Trait Reroll as well, making Moon Slayer arguably the best consistent source of reroll currency in Sea 1. A Dungeon Key drops at 30%, which is worth holding onto for dungeon access. Rarer rewards include Demon Remnant at 13.41%, Lunar Essence at 4.63%, Moon Outfit at 1.22%, Crescent Shard at 1.06%, the Six Eyed Demon Title at 0.7%, and the prestigious Moon Crest at 0.45%.

For farming runs, stack damage-boosting accessories and come with a reliable combo to burst health chunks efficiently. The guaranteed rerolls make every single kill profitable regardless of whether the rare cosmetics land.