Crocodile

 The croc comes to us in two sizes - the basic crocodile and the primeval deinosuchus. Despite clocking in at a measly level 2, the crocodile has one of the deadliest abilities in the game - death roll. Once you drown a PC in knee-high water, you will get a reputation as that GM.

The Milzeezipee river is a great route for logs, cut in the north and transported downstream. Unfortunately, some gators have realized folks who try to steal single logs from the massive groups make for easy food, and gator hunting season has been called for. Each gator will net you ten gold, and the hunter who bags the largest of the beasts will get another thousand, along with a magical machete. 

A group of grizzled mercenaries is approached by a strange man in a beige robe called Stevanos Irwinos. He wishes to (for some insane reason) catalogoue the crocodile population of the Nakhunta glades. The catch is, he wishes no harm on the animals. As the glades are treacherous and full of dangers, he needs protection.
Even as a legendary deinosuchus - a crocodillian beast the size of a small house - capsizes their boat, Stevanos keeps trying to calm the situation down and urges his compatriots not to hurt the beast. If they listen, they are rewarded a single scale from the lizard king when their ordeals are over - allowing them to summon an entire army of dinosaurs as a one-time boon.

Legend holds it that if a lizardfolk egg is swallowed whole by a dire crocodile, it will immeddiately hatch and give birth to a mighty champion of the swamps. A militant iruxi shaman now summons a troupe of foreigners he once nursed back to health, and asks them to help him devise a plan of action. He wishes to distribute as many eggs over as big of a territory as he can, hoping to raise a physically enhanced warbands.
Of course, even if they know of a way to help him, the foreigners are at a conundrum - such a warband would surely be used for invasion. On the other hand, the sanctity of an owed favour is not to be carelessly broken...