5 mercenary Cobra's deploy when your Base is under attack.
More Information and a the Full List of Ops available here: Special Ops
The Level 10+ Cobra have the same range as the Level 10+ Warhawks.
The Level 10+ Cobra "does substantially more damage to most Infantry Units".
Because of the Cobra's ability to heavily damage Infantry Units, they are often grouped with Warhawks or Hellstorms to aid in the killing of Last Stand Infantry.
Despite the "enhanced" ability to damage Infantry Units at Level 10+, the Cobra continues to list just an 'OK' Damage Filters Rating against them.
A level 10 Airfield can house a total of 23 Cobra's with the space of 20 left unused.
The Cobra might not have the range of the Hellstorm but it has the advantage of being precise in the elimination of targets and only destroys what is intended, The Hellstorm, with its large Splash Damage, can destroy unintended targets causing "Last Stand Unit" problems.
The Cobra flies at a higher altitude than theHellstorm, see pic in gallery.
There seems to be 2 rocket launchers under the wings of the plane, but the description says it uses a MG3 mounted on his wings (MG 3A1).
Although cobras are named after a real attack helicopter (The AH-1 Cobra), they bear no resemblance to it.
The achievement for unlocking the Cobra is called "Cobra Command", which is a reference to the fictional nemesis of the G.I Joe team in the animated G.I Joe series.
Cobras are lightly armored helicopters mounted with twin MG 3 machine guns and the mobility to mow down infantry units.
— In-game description
The Cobra is a light helicopter armed with twin MG 3A1 machine guns, mowing down infantry from above in record time.
— Level 10 description
Cobra Flight Altitude vs Hellstorm
Cobra is shooting the Mortar Tower (Mortar Turret).