Overseers used to have similar special abilities as the overlord, but those were removed. * Excrete Creep * The overseer can create a small patch of creep, the radius steadily expanding as long as it remains stationary. This ability is researched at the evolution chamber. * Slime (also known as "Corrupt Minerals") * The overseer can drop a non-attacking slime creature, temporarily disabling resource nodes and xel'naga towers. The slime can be attacked and removed by other forces. The minerals can be covered as they're being harvested, enabling raids which slow down an enemy's economy. The creature must be killed before the minerals can be accessed. * This ability took time to "cast" and had a small cooldown timer.