Bone Cracker

Were you looking for the Halo 2 Vista achievement of the same name? The Bone Cracker (Beat Down in Halo 3 and Pummel in Halo: Reach) Medal is awarded for killing an opponent with a melee attack that does not assassinate him (a melee attack from behind). It is available in all Multiplayer gametypes and has a Bungie difficulty rating of 3 out of 10.

It is represented by an inverted silver star with a dark green fist. After you kill an opponent with a melee attack, a message appears on your screen that says: "You beat down (player's name)". It is also awarded if a Covenant Energy Sword or Gravity Hammer is used to kill an opponent with the right trigger. In Halo: Reach, after killing an opponent with a melee attack, the message "You pummeled (player's name)" will appear.

Tips

 * A common way for players to get the medal at the same time is to get a Double Beatdown.
 * A simple method to earn this medal is to play Grifball.

Trivia
The "Green Fist" could be a reference to the Incredible Hulk; the Hulk uses his powerful fists in battles. It may also depict a MJOLNIR-armored gauntlet.