Harvester’s Night Mod 1.12.2 add in the Match The Harvester.
He’s a boss who occasionally spawns through the evening. It’s possible to spot his entry by a lightning attack followed by his menacing bliss (if you are near enough). Kill it before the day rises and you’ll be rewarded with his scythe, a potent tool for mowing down grass, flowers, and leaves. He’s not designed to be a difficult boss, because he’s supposed to battle early in the game, where his falls will be the most useful. Spawn speed and measurement white/blacklist are configurable.