Deathstreak

Deathstreaks are a feature (similar to perks or killstreaks) in Call of Duty: Modern Warfare 2 and Call of Duty: Modern Warfare 3. The purpose is to give the player a consolation in order to motivate them to get back into the game after dying a certain amount of times without a kill. Their effectiveness is limited in order to discourage players from intentionally dying in streaks to activate them. They will activate upon each respawn the player has after the necessary number of deaths until a kill is scored. When the deathstreak is snapped, the deathstreak perk remains in effect for the remainder of that life; the following respawn will not have the deathstreak active.

Deathstreaks available in Modern Warfare 2
The number of deaths required for a particular deathstreak can be reduced by one when using the Hardline Pro Perk.

Trivia

 * Suicides, deaths by teammates in Hardcore or penalty deaths (from ricochet damage or teamkilling) do not count towards deathstreaks. However, these deaths will end a killstreak (even though the player wasn't killed by an enemy).
 * Originally, Dead Man's Hand deathstreak was supposed to appear in Call of Duty: Modern Warfare 2, but later removed from the final version. It is now set to appear in Modern Warfare 3.