Giant Fire Snail
The giant fire snail peacefully munches on rocks and ores in mountain mines. Some dwarves have taken up snail wrangling. Feeding the snails impure ores and collecting more purified metals as waste from the snails.
Giant Marsh Snail
The giant marsh snail has thick, hardened hide protecting it from the many predators in the marshes. Some say the metallic sheen is from the types of mushrooms it is frequently seen eating.
The diplodocus is home too many marshes and swamps of the worlds. It is typically a docile animal, however its long tail and large feet can cause significant damage if you are close enough to get hit when the excited diplodocus spots a tasty snack.
The spinosaurus can be found chasing giant fish in vast swamps, large rivers, and some costal areas of the world. While a fierce and hungry predator it will pass up many land dwelling creatures in favor of fish snacks.