The Fire Swamp is a biome from the Twilight Forest mod. This biome is similar to the Twilight Swamp, only it has lava pools instead of water pools, and scattered around the ground are Smoking Blocks and Fire Jets. The colors of blocks like vines, leaves, and grass are red instead of green in this biome. Any water within this biome is turned into a deep purple color instead of a sea blue. Hydra Lairs are commonly found in these biomes.
If the player hasn't killed the Minoshroom and they attempt to walk in this biome, they will be burned. If they find a Hydra Lair during this time, the Hydra will be invulnerable to damage while the Progression Shield is active.