Glurpers, a Danger to Mankind and Glurperkind Alike

There is an old poem that mothers have used to warn their children of a creature that has plagued the kingdom as long as can be remembered.
If you should come across a swamp / Or to a marsh your feet should stomp
Take ten steps back then run away / For in those waters, so they say
The glurpers lurk, with bulging eyes / With warts, webbed feet, and gurgling cries
They'll snatch you up, like frogs with flies / As they leap through the air
Beware my son, and listen well / Take care my daughter, no magic spell
Can save you once you're in it's hold / It won't be swayed by jewels and gold
Beware my child, for if you hear / A cry that fills your heart with fear
It means that glurpers have drawn near / Beware my child, beware!
Glurpers are amphibious creatures resembling frogs, if frogs were bipedal and the size of a man that is. The common glurper stands at about six feet (almost two meters) tall, while lesser glurpers, a smaller variety of glurper commonly mistaken for juveniles, grow up to three feet (nearly a meter) in height.
The offspring of these anuran creatures hatch from clutches of soft eggs layed in bodies of freshwater. When the eggs hatch, the baby glurpers (also known as glurplings) resemble a bulbous overgrown tadpole, weighing about nine pounds (four kilos). The early hatchers immediately begin devouring their eggs and then move on to the unhatched eggs of their unfortunate siblings. The ones that do survive feed on fish and frogs until they begin to sprout legs and start hunting larger prey.
Glurpers have been a natural predator of humans as long as they've been around. They have the intelligence to use rocks and sharp sticks as makeshift weapons and with their powerful legs can easily leap above a person's head, covering ground rapidly. The main deterrent to mankind's demise from these creatures are themselves.
Cannibalistic in nature, glurpers will not hesitate to devour one another, whether it be an adult eating eggs and young or a common glurper swallowing their smaller cousins. That being said, they are still a very dangerous threat and should be hunted and culled during cold dry months when they hibernate.