Invisible

Invisible is a new perk featured in Call of Duty: Covert Ops. It features some elements of the perk Ghost from Black Ops.

Overview
Invisible allows to player to appear invisible to infrared scopes and Sentry Guns. This can allow players to get past corners with a Sentry Gun, or counter-snipe a sniper using infrared. Invisible is very useful for stealth classes, and is good paired with Ninja.

Amateur Challenges
Killstreak Destruction: Destroy 20 killstreaks using Invisible.

Silencer Kills: Get 150 kills with a weapon with a silencer attached.

Close Range Kills: Get 50 close range kills.

The Amateur version allows the player to be invisible from all killstreaks. However, they can still be seen in enemy controlled killstreaks, minus the red box above the head. Also, when targeted a name won't appear and the crosshairs won't turn red.

Pro Challenges
Killstreak Destruction: Destroy 50 killstreaks while using Invisible.

Eye in the Sky: Get 50 kills with a UAV or Counter-UAV in the air.

Close Range Kills: Get 100 close range kills.

The Pro version allows the player to not appear on the enemy map. The player is also given an "invisibility suit" which makes the player invisible for 10 seconds, and for 15 seconds with a UAV in the air. After the seconds are up the suit must recharge for one minute.