The Mosquito is a guided missile and secret gunpod. When collected, it fires at least one missile at a time, though it's direction can be controlled through the movement of the fighter. Damage from this gunpod is relatively high.
As the Mosquito is a secret gunpod, it must be found. It's only known location is in the Factory area of level 4. As soon as you enter the area, maneuver to the very bottom of the area where you will come across several containers. Firing a gunpod that shoots backwards (i.e. a Spreader or Grenade) at said containers will release the Mosquito for use.