SCP-066 is currently replaced by SCP-178.
SCP-066 is a Euclid-class SCP that appears like a large pile of yarn that appears to have the eyes of a normal human being. The SCP itself never actually worked, but what it was supposed to do is deafen the player and trip them.
SCP-066 was contained to the left of Sector 2 after entering from Sector 3. It is located on the left side.
SCP-066 was not aggressive at all, but when it did breach it would roll around the map and not do anything to any players.