A frog-like race that has taken up residence in Surferio. Greems can breathe through either lungs or gills, so they can live on land as well as underwater.
To be more precise, they need to live both on land as well as underwater and cannot survive with access to only one of the other environment. Greem skin dries in the air, and Greem bodies are too fragile to withstand a high level of water pressure for long. Therefore, Greems must live near clear and shallow bodies of water.