Reach the indicated number of kills to unlock the corresponding bonus.

Spy Plane: 3 kills; shows enemies on the mini-map (free).
RC-XD: 3 kills; remote control car with explosives piloted by killstreak user (1,200 points).
Counter-Spy Plane: 4 kills; temporarily disables enemy's mini-map (1,600 points).
SAM Turret: 4 kills; airdrop a turret that destroys aircraft (1,600 points).
Care Package: 5 kills; airdrop a crate that contains a random killstreak, ammo crate, or special weapon (free).
Napalm Strike: 5 kills; airstrike drops fire over an area of the your choice which burns and damages enemies temporarily (2,400 points).
Sentry Gun: 6 kills; airdrops anti-personnel sentry gun (3,200 points).
Mortar Team: 6 kills; user targets three locations to be shelled by mortars (3,200 points).
Attack Helicopter: 7 kills; call in automated attack helicopter to a selected location (free).
Valkyrie Rockets: 7 kills; two remote controlled rockets (4,000 points).
Blackbird: 8 kills; advanced version of the spy plane that indicates enemies on the map and direction they are facing (4,500 points).
Rolling Thunder: 8 kills; B-52 bomber bombs selected location (4,500 points).
Chopper Gunner: 9 kills; control door-mounted mini-gun from a helicopter that circles the map; enemies without the Ghost perk are displayed as red dots (5,000 points).
Attack Dogs: 11 kills; call in a group of attack dogs (6,000 points).
Gunship: 11 kills; pilot a helicopter with rockets and machine guns; helicopter can be destroyed (6,000 points).