Flag Kill

The Flag Kill Medal medal is awarded for killing an opponent by meleeing your enemy with the flag. You get this medal in addition to the Beat Down medal. It is represented by a white eight-pointed star with a red flag in the middle.

Trivia
 * On your Halo 3 Career Stats at Bungie.net, the description for the flag is 'Its right next to the headlight fluid'. This is homage to the series Red Vs. Blue, where the red team sends the rookie Donut to the store for elbow grease and headlight fluid.  Instead, he mistakenly goes to blue base and takes their flag.