Which one?
Gold: unlock all attachments
Grey/Silver: 500 kills (need to be prestige)
Grey/Silver with headshot icon: 250 headshots
White Skulls: 2500 kills
Gold Skulls: 1000 headshots
check here for all the titles and emblems: http://callofduty.wikia.com/wiki/Callsigns
You have to get 10000 kills with the intervention.
when you are level 4 you unlock the intervention and 50 cal.
Well, as you all know the 'Ta-Da!' title is VERY rare. I know how to unlock it! What you have to do is you have to kill 25 players within 5 seconds after respawning on a Tactical Insertion. That's how you unlock the 'Ta-Da!' title!
you unlock it by getting 50 kills with the stealth bomber. this is the Spirit 1 challenge.
Achieve 1000 headshots with the ACR. You must be prestiged at least once to unlock this challenge.
get to level 48 and you unlock the ACR
when you are level 4 you unlock the intervention and 50 cal.
To unlock the Intervention emblem, you must get 1,000 kills with the Intervention after Prestiging at least once.
get 2500 headshots
do some challenges they will unlock it for you ------------------------- Completing every challenge will unlock every title.
unlock all the attachments or get 500 or more kills with it when you have prestiged
Stab 250 enemies with your knife. You must have prestiged at least once to unlock this challenge.
kill an enemy by starting a chain of explosives. (or enemies)
kill 250 people with melee (knife, tactical knife)
You have to achieve the Mastery challenge for that weapon. That is, unlocking all attachments.
Well, as you all know the 'Ta-Da!' title is VERY rare. I know how to unlock it! What you have to do is you have to kill 25 players within 5 seconds after respawning on a Tactical Insertion. That's how you unlock the 'Ta-Da!' title!
get 50 kills with a stealth bomber, however you must have prestiged first
you unlock it by getting 50 kills with the stealth bomber. this is the Spirit 1 challenge.