The Supervisor is a Scrin entity which commands the Tiberium (or Ichor as it is know to the Scrin) harvesting of Foreman 371 on Earth in 2036, and possibly harvesting operations on other worlds. Little is known about the Supervisor, including whether it is a life form or an artificial intelligence. Intercepted transmissions show it having an insectoid form, however, it is unknown if this is an avatar or the Supervisor's true appearance. The Supervisor views success in its mission as the most important goal, placing it above even the survival of its subordinates.

Shortly after Foreman 371 deployed on Earth to begin harvesting operations on the planet after detecting a liquid Tiberium explosion, his ships were fired on by the Global Defense Initiative's ion cannon network. This led the AI controlling the Scrin mothership to recommend retreating after discovering that Earth was not a dying, Tiberium infested planet, but a world with two powerful, rival factions.

The Supervisor, however, overrode the mothership AI's recommendations and ordered the Foreman to deploy his military escorts to attack cities on Earth, in order to distract both GDI and the Brotherhood of Nod while his harvesting crews begin constructing the interplanetary portals, or "Thresholds" to a location known as the Ichor Hub, possibly a Scrin base or even their homeworld. These portals would allow the Scrin to both extract Tiberium from Earth and possibly deploy reinforcements.

Unfortunately for the Foreman, he encountered heavy resistance from both GDI and Nod. In spite of this, the Supervisor refused to call off the mission and ordered the Foreman to investigate the ruins of Nod's Temple Prime, where he found data on Kane, whose DNA was already in the Scrin database, but was of unknown origin, differing from both human and Scrin DNA.

The Scrin harvesting operations would be ended when GDI destroyed all but one of the "Threshold Towers", which was defended by Nod on the orders of Kane, who believed it necessary for his Ascension. Sensing his inevitable defeat, the Foreman retreated through the portal for the Ichor hub, against orders from the Supervisor, who ordered him to stand his ground even at the cost of his life.

Shortly afterwards, GDI destroyed a control node that supplied Tiberium radiation vital to Scrin forces in the field, instantly killing all Scrin forces on Earth. Meanwhile, the Supervisor contacted the Scrin Overlord, who cared little about the Foreman's insubordination, but ordered a full scale invasion of Earth. In spite of the foreman's threat, as for the 2080s, the Scrin have not been seen on Earth again.