Spore Sac

The Spore Sac is an accessory that is obtained from Plantera's Treasure Bag which you get from killing Plantera in Expert Mode. When equipped, it rapidly spawns multiple spores around the player that will try to attack any nearby enemies. They explode on contact dealing about 400 damage over 1 second and inflict Poisoned debuff. This effect has a small AoE, so it can hit more than 1 target. If multiple spores attempt to attack one enemy that dies (no matter how) before all of them reach, they will stop and not be destroyed.

While the spores are slow and have no hope to outrun monsters, most enemies will be running at you. This means that if you stand still your spores will not have trouble intercepting incoming threats. Caution must be exercised while moving however, as you will leave your protective flock behind, and any threat in front of you will have a window of opportunity to reach you.

The spores can freely pass through blocks, and will chase (and damage) enemies behind and through them. This is especially useful when dealing with enemies like Wraith or Angry Trapper, since it will engage them before they can even reach the player. This also becomes useful when exploring "pocket" caves - you can move close to the wall and let spores deal with enemies inside before entering yourself.

Tips

 * Spores cannot appear in liquids.
 * Spores will not actively intercept destructible projectiles (such as one fired by Dark Casters), but if the projectile hits them it will be destroyed.
 * Spores seem to not trigger the teleportation effect of Hardmode casters in the Dungeon, thus being an efficient way of killing them.
 * This item is especially good in tight spaces and against enemies that pass through walls, like those found in the Dungeon or Underground Jungle.
 * One very handy use of spores is to fend off any minor attacks while building. Enemies will be killed without you having to switch away to combat items.
 * This item may be useful for designing AFK Farms as the spores will automatically spawn and damage enemies.

Anomalies

 * The spores spawn around nearby tiles or walls, meaning that if the player is flying or on a platform without any tiles or walls nearby, spores will not appear. It is possible to clump the spores due to this.

History
Sac de Spore