Start the quest in the eastern Feldip Hills by speaking to Rantz. The first task he gives you is to make some "stabbers", also known as Ogre Arrows. Please note that you can't just buy some from the Grand Exchange - you have to make them yourself!
First things first, get 5 wolf bones by either killing the wolves to the west of Rantz or by purchasing them. Use chisel your on them to create wolfbone arrowtips. Head back towards Rantz and chop 5 nearby Achey trees to get their logs.
Use your knife on the logs to create some arrow shafts, then add feathers. Last but not least, use your wolfbone arrowtips on the flighted ogre arrows to make your ogre arrows!
Return to Rantz and he will take 6 of them. He will tell you that to be able to hunt the chompy you will need to have the fatsy toadies. Head north and enter Rantz's cave. Talk to either Bugs or Fycie and you will learn that the kids blow up the toads with swamp gas. The bellow that they use to do this is locked up in the Ogre Chest in the northwest corner of the cave.
Right-click on the chest and select the option to "Unlock Locked Ogre chest". If you fail, your strength will be temporarily lowered by one level. Try to "unlock" the chest again.
Now search the chest and you will find a pair of ogre bellows. Exit the cave and then head to the pond near where the wolves are. Use the ogre bellows on a swamp bubble in the pond to fill it with swamp gas, then use it on 3 nearby toads. You will automatically pick up the bloated toads. Take these toads to Rantz.
Rantz will tell you to place the fatsy toadies in a clearing just south of where you stand. Go drop the bloated toads on the clearing. A chompy bird will soon arrive and Rantz will shoot at the chompy bird and miss. Rantz complains that your arrows are the problem. Ask him for a try at it.
Place some more toads and when the chompy appears, kill it and pluck the carcass. Pick up the meat and talk to Rantz. He will want you to cook it with the different seasonings he and hid kids wants.
Go inside the cave and ask the kids what they would like. Each players gets told differently; here is a map of their locations:
Once you have collected all the seasoning you need, head to the spit-roast just outside of Rantz's cave. Use the chompy on it and you will automatically add the seasonings. Take the food to Rantz and...