sillyBe warned, though, I didn't exactly follow the SR4A rules on this.
Gnats of Doom
These hybrid-form insect spirits are more nuisance than true threat, though one should be careful as even small critters can cause serious damage in large numbers. The gnats never attack by themselves, preferring instead to swarm individuals that they see as a threat.
B A R S C I L W M Edg
3 3 3 3 3 3 3 3 3 3
Ess Init IP
3 10 2
Condition Monitor Boxes (Physical/Stun): 9/9
Armor (Ballistic/Impact): 6/6
Astral INIT/IP: 10 / 3
Movement: 15/50
Skills: Assensing 3, Astral Combat 3, Dodge 6, Gymnastics 4, Perception 6, Unarmed Combat 3
Powers: Animal Control (normal gnats), Astral Form, Banishing Resistance, Concealment, Dual Natured, Enhanced Sense (Smell), Hive Mind, Inhabitation (Living Vessels), Movement, Natural Weapon (DV 4P, AP 0), Sapience, Swarm, Toughness (+2 to all Damage Resistance Tests)
Optional Powers: Annoyance, Bite, Confusion, Disorientation, Guard, Pestilence, Sonic Projection
Weaknesses: Allergy (Insecticides, Severe)
Gamemasters, have fun torturing your players with the GoD (oh, hey, funny how that acronym works. =). Because, darnit, player characters were made to be tortured. Right?