Unarmed Marine
From Halopedia, the Halo wiki
Summary
Start a new game on the level Truth and Reconciliation. Look at the marine in the back of the pelican at the start of the level. Before he gets out, he has no weapon. His hands look like he's holding an assault rifle, but there is no assault rifle. An Assault rifle appears in his hand after he gets out, though.
NOTE: This may not appear on all copies of Halo PC, it may not even appear for any copies of the xbox version.
