The Unknown Ghillie Camouflage is a weapon camouflage skin seen in Call of Duty 4: Modern Warfare. It physically looks like the Ghillie Suit design. Unlike other camouflages, it isn't just a paint on the weapon, rather it is like the suit on the weapon.
It is exclusively seen on the M21 in campaign mode. It is only used in the levels "Blackout" and "All Ghilled Up". It can also been seen in "F.N.G" on the weapon racks, but like all other weapons, can't be picked-up.