From Pathfinder Beginner Box: Secrets of the Unlit Star, which isn't enabled.

Giant Fly (BB)

CREATURE 1

This massive fly's twitching limbs seem to never stop moving as it constantly cleans itself and scoops anything edible into its mouth parts. While primarily carrion eaters, giant flies sometimes prey on livestock or other animals too slow to get away. Left to their own devices, these flies will lay dozens of eggs within the mostly-eaten carcasses. These eggs soon hatch into enormous maggots that begin the cycle of scavenging anew.

Perception +8; darkvision

Skills Acrobatics +7, Athletics +6

Str +3, Dex +4, Con +3, Int -5, Wis +3, Cha -5

AC 16; Fort +6, Ref +9, Will +6

HP 20

Avoid the Swat

Trigger The giant fly is targeted with a melee or ranged attack by an attacker it can see

Effect The giant fly gains a +2 circumstance bonus to AC against the triggering attack. If the attack misses, the giant insect can Fly up to its fly Speed.

Speed 20 feet, climb 20 feet, fly 40 feet

Melee Mandibles +8, Damage 1d6+3 piercing plus Fly Pox

Fly Pox (disease)

A giant fly could carry any disease, but most transmit an infection called fly pox with their bite. A character who is critically hit by a giant fly's mandibles must succeed at a DC 16 Fortitude saving throw or be Enfeebled 1 for 1 day.

Pathfinder Beginner Box: Secrets of the Unlit StarORC