Attrition is an upgrade for COBRA. It allows players to either steal 2 lives from their opponent (on Assault Mode) or add 2 lives to themselves (Defend Mode) once every 15 seconds. Many of these can be a threat for opponents in Assault mode and considered an overpowered upgrade to many - especially to newer players.
Exactly 75 Attritions (19 minutes w/ 1 COBRA or 15 seconds w/ 75 COBRAS) is needed to bring an opponent down to 1 life in Assault mode (as long your opponent does not Attrition you back or use the Support Chinook ability), or to go to full health in Defensive mode.
There is a glitch that if a player gains more than 150 lives with the Support Chinook ability and then uses Attrition, the amount of lives resets back to 150.
When looking at the game code, the way in which Attrition's life-gaining capability works isn't simply just a gain of lives. In the game code relating to the Attrition algorithm, the game actually generates a Support Chinook crate worth 2 lives that picks up automatically.
The file that the code for this is in is called "CobraMonkeyLifeVampire.weapon", instead of something like "CobraMonkeyAttrition.weapon".