Critter

Firefly

Health: 2
Armor: 0
Speed: 11
Spawns in: 24 biomes

Where it spawns (24)

Biome	Share
Snow SurfaceSurface · critter tableOnly under a condition the table can’t show	48%
TempleDungeons and Temples · critter tableOnly under a condition the table can’t show	43%
Swamp SurfaceSurface · critter tableOnly under a condition the table can’t show	42%
Forest SurfaceSurface · critter tableOnly under a condition the table can’t show	41%
Pirate VillageSurface · critter tableOnly under a condition the table can’t show	41%
Plains SurfaceSurface · critter tableOnly under a condition the table can’t show	41%
DungeonDungeons and Temples · critter tableOnly under a condition the table can’t show	16%
Forest Deep Cave IncursionIncursion · critter tableOnly under a condition the table can’t show	16%
Snow Deep Cave IncursionIncursion · critter tableOnly under a condition the table can’t show	16%
Swamp Deep Cave IncursionIncursion · critter tableOnly under a condition the table can’t show	16%
Desert Deep Cave IncursionIncursion · critter tableOnly under a condition the table can’t show	16%
Slime Cave IncursionIncursion · critter tableOnly under a condition the table can’t show	16%
Graveyard IncursionIncursion · critter tableOnly under a condition the table can’t show	16%
Spider Castle IncursionIncursion · critter tableOnly under a condition the table can’t show	16%
Forest CaveCave · critter tableOnly under a condition the table can’t show	12%
Plains CaveCave · critter tableOnly under a condition the table can’t show	11%
Forest Deep CaveDeep Cave · critter tableOnly under a condition the table can’t show	11%
Snow Deep CaveDeep Cave · critter tableOnly under a condition the table can’t show	11%
Desert CaveCave · critter tableOnly under a condition the table can’t show	11%
Desert Deep CaveDeep Cave · critter tableOnly under a condition the table can’t show	11%
Snow CaveCave · critter tableOnly under a condition the table can’t show	11%
Plains Deep CaveDeep Cave · critter tableOnly under a condition the table can’t show	10%
Swamp CaveCave · critter tableOnly under a condition the table can’t show	8.8%
Swamp Deep CaveDeep Cave · critter tableOnly under a condition the table can’t show	8.8%

Drops

One ofYellow FireflyGreen FireflyBlue FireflyAlways

Mobs

Health, drops and the three Forest Cave mobs behind spawn gates

Data updated 26 Oct 2026

Of the 157 non-boss mobs, 88 are hostile. 3 only enter a spawn table once you pass a days-played, armor or max-health mark, so a creature missing from your caves is usually waiting on your progress.

How Mobs Work

Difficulty

Health and damage both follow the world difficulty. Entries show casual through brutal side by side, so read the column for your own world.

Spawn Gates

Three things can hold a mob back: days played, armor and max health. Until you cross the mark it is not in the table, which is why early caves feel tame.