May grow from the giant tree located just outside of the upper exit in Firelink Shrine.
The seed has a 10% chance of appearing after the player has been invaded for the first time. From then onward, the chance of it spawning increases by 10% for each following invasion, up until it either reaches 50% or the seed spawns. Once the seed has been collected, the drop rate will return to 0% and the process will repeat once more.
The seed needs to be collected in order for another to spawn. If the seed spawned but was not collected and the player got invaded in the meantime, these invasions will not count toward the next appearance of a seed.
Consuming this item will make all enemies in the level to turn hostile against invaders.