I see the giant mantis as following the B-actor-made-good plotline. A big splash early on—1957’s The Deadly Mantis, naturally—followed by years of toiling in the business—decades of PBS nature specials—only to be rescued, like John Travolta or Mickey Rourke, by the right part written with him in mind—the scion of Golarion’s assassin god. Way to tough it out and seize the spotlight, giant mantis! But if assassins aren’t your bag, here are some more mantis adventure seeds for your home campaign…
A dragon abducted the princess in the blink of an eye! Or so say the terrified eyewitnesses, who only saw a green flash and a blur of wings. But the standard save-the-princess narrative falls apart when the rescue party finds the real culprit—a treebender mantis. The princess is long dead, the mantis is out of the party’s league, and the king will execute them if they do not return with a live daughter and a dead dragon’s head.
The assignment is a simple one: help svirfneblin take their fire beetles to market. A journey of 25 leagues underground, the travelers must contend with cave-ins, poisonous fungi, and the fire beetles’ natural predators, a cave-dwelling species of giant mantis.
A brotherhood of half-elven rangers teaches outcasts a rare two-weapon fighting style. The price of admission is the head of a giant mantis.
—Pathfinder Bestiary 200