Ironback

Ironback is a consumable item obtainable from fishing.

Fishing
Ironbacks can be obtained by fishing. In order to catch Ironback, the player's hauling level has to be at least 79. Ironback have a weight of 200.

They grant 7800 xp for the Hauling skill when caught.

Other methods
Ironbacks can also be obtained by opening a Fish Case.

Usage
Ironback is a consumable item, and can be consumed at any time by holding the use button while holding it. Ironbacks offer minimal hunger and saturation but heals the player by health if consumed.

Gnawer
Ironback can be fed to a gnawer. Feeding one to a gnawer will heal health to the player and do  damage to the gnawer.