
Goldfish, Bunnies, and Penguins turn into Corrupt Goldfish / Vicious Goldfish, Corrupt Bunnies / Vicious Bunnies, and Corrupt Penguins / Vicious Penguins respectively.Zombies and their counterparts become able to open Doors.Enemies can spawn near towns, even though those normally suppress enemy spawns.Spawn rates below the surface remain the same. It only affects spawn rates above the surface.This works no matter the environment, so for example Corruption and Crimson enemies can swarm more than they normally would.Not only do they spawn faster, but more are spawned than can normally exist on-screen at once. The spawn rate of enemies on the surface increases.It is possible to have four or more Blood Moons in a row and, conversely, a Blood Moon will not necessarily occur even over the course of many in-game weeks. Every nightfall has an equal chance of being a Blood Moon and does not change if the previous night was a Blood Moon.

Whether a Blood Moon will occur naturally is determined at dusk each night.

In order for a Blood Moon to naturally occur, the following criteria must be met :
