Grenwall spikes, worth 145 each, are used as an ingredient in extreme ranging potions. Grenwalls may be caught in Isafdar by baiting box traps with raw pawya meat. The traps must be baited in order to catch the animals. When caught, grenwalls yield bones, between 18 and 21 spikes, and occasionally a grimy herb. Bait is always lost when a trap fails, and usually lost when the catch is successful. There is a small chance that the bait will be recovered.
Due to the isolation of areas in which a player may catch grenwalls and the long distance from any bank, it is generally better strategy to catch pawyas first and then use their meat to catch grenwalls. It is required to bait traps for catching pawya with a papaya which may be easily produced as a product of casting the fruit bat's scroll. Using a fruit bat to catch pawya for their meat not only significantly lowers the amount of money that must be invested to catch pawya (which also creates a large cost for failing to trap), but it also allows for longer stays rather than travelling back and forth between a bank to restock on bait. Lengths of trips are limited only by the number of fruit bats and scrolls carried. For longer stays, it is wise to bring super restores or summoning potions to keep summoning points up.
If you have not completed Deadliest Catch, it is recommended to catch grenwalls either at the hunting area east of Port Tyras or just south of the Elf Camp. However, completion of Deadliest Catch unlocks a bank deposit chest just south of the Elf Camp. It is strongly recommended to hunt south of the camp if this chest is available.
Another small benefit of the spot just south of the Elf Camp is that it is in the vicinity of an impling spawn point. If the lower level implings are hunted diligently, it allows more sought after implings (namely dragon and kingly) more chances to spawn. The practical approach is to catch unwanted implings barehanded and thus instantly loot them without wasting a jar, but catch the expensive implings in a jar and bank them afterwards. Using a jar generator will essentially grant 33 impling jars in one inventory slot.
Camouflage gear does not improve the chances of catching grenwall successfully, and standing too close to the traps may deter the grenwall from taking the bait. If a trap fails, it must be re-baited with raw pawya meat.
This does not take into account the Private Hunting area, accessible from the Big Chinchompa minigame. With that and the Trianwn quiver 2 and arctic bear familiar it is possible to achieve over 200 catches per hour (at around 85 Hunter). However, with the use of scentless potion and Arctic Bear familiar and at level 99Hunter, one is possible to achieve well around 300 to 350 catches per hour.