[jokrj]

Head Pieces

Spartan (10)
Mark VI.....Avaiblie at start
CQB...........Availible at start
EVA.................Complete Campaign on Normal, Heroic, or Legendary
EOD.................Complete Campaign on Legendary
Security...........Earn 1,000 Gamerscore Points
Scout................Unlock "Used Car Salesman" Achievement (Destroy an enemy vehicle containing 3 enemies in Campaign or ranked playlists)
Mark V.............Unlock "UNSC Spartan" Achievement (Reach Sergeant ranking online)
ODST...............Unlock "Spartan Graduate" Achievement (Earn 5 EXP or complete 10 ranked matches)
Rogue.............Unlock "Spartan Officer" Achievement (Advance to the Spartan Officer ranks online)
Hayabsa......All 13 skulls found
Elite
Flight...............Complete Campaign on Heroic or Legendary
Ascetic.............Unlock "Steppin' Razor" Achievement (Get one triple kill with an energy sword in ranked FFA)
Commando....Unlock "Overkill" Achievement (Get one overkill)

Shoulder Pieces

Spartan (7)
Mark VI.....Avaiblie at start
CQB...........Availible at start
EVA.................Complete The Ark on Normal, Heroic, or Legendary
EOD................Complete The Ark on Legendary
Security..........Earn 750 Gamerscore Points
Scout...............Unlock "We're in for some Chop" Achievement (Destroy an enemy vehicle with a piece of equipment in a ranked playlist or campaign)
Hayabusa......9 skulls found
Elite
Flight...............Complete The Ark on Heroic or Legendary
Ascetic............Unlock "Overkill" Achievement (Get one overkill)
Commando....Unlock "Killing Frenzy" Achievement (Get one killing frenzy)

Body Pieces

Spartan (6)
Mark VI.....Avaiblie at start
CQB...........Availible at start
EVA.................Complete Tsavo Highway on Normal, Heroic, or Legendary
EOD.................Complete Tsavo Highway on Legendary
Scout...............Unlock "Too Close to the Sun" Achievement (Destroy an enemy banshee with the Sp'laser or missile pod in a ranked playlist or campaign)
Hayabusa.....5 skulls found
Elite
Flight...............Complete Tsavo Highway on Heroic or Legendary
Ascetic............Unlock "Up Close and Personal" Achievement (Kill 5 enemies via melee or assassination in a ranked FFA playlist)
Commando....Unlock "Triple Kill" Achievement (Get one triple kill)


Comes from the Official Strategy guide.

What's interesting is that in-game it clearly states there are 10 Spartan Head permutations, however the following picture has 11.



stole some of this from wiffleballtony, his much more comprehensive list can be found here: http://www.bungie.net/Forums/posts.aspx?postID=13113493

[MeikenhousIsBak]

thank you very much for this information!

[bRUTAL]

God all skulls for the samurai helmet.

[-RaiN-]

Whats the difference between the Ninja and the Samurai helmet? Are they different?

[checK yuR pulse]

anyone know a website that shows you where all the skulls are?

[Sabbathkicksass]

Security..........Earn 750 Gamerscore Points

friend of mine has like 860 points in it and it doesnt unlock for him.

[johnthehero]

Some of these are inaccurate, despite supposedly coming from the guide. I mainly want the Security shoulders, and I have 860 Gamerscore in Halo 3 and no shoulders. I also have the We're In For Some Chop achievement and no Scout shoulders.

(I am the friend in the above post)

[Hobb]

thats sweet i guess i wish you could record out of campaign

[johnthehero]

This is a pretty good guide for the 9 achievement skulls:
http://hushedcasket.com/node/2375/

No one outside of Bungie has all 13 yet-- the last one, IWHBYD, is supposed to be very well hidden. You can get the Hayabusa armor and shoulders for getting all the achievement skulls, though.

[Gallagher06]

thanka, been wonderin how to unlock the hayabusa head piece