Magma Fish is used to pacify Flame Penguins when they are hostile. This will only work if you are wearing a full suit of any penguin armor. When right-clicking a hostile Flame Penguin with a magma fish, there is a chance it will become neutral again, signified by smoke particles from the Flame Penguin. Magma fish can also be consumed for as much hunger restored as regular cooked fish.
Crafted with raw fish and magma cream. (This recipe is shapeless.)
Alternate recipe for magma fish, making it far easier to obtain if you have multiple fish:
1.2.5e: Alternate recipe added.