Slag elementals are a type of elemental conglomerate found in Draenor. They appear to be fire elementals and earth elementals forced and kept together with metal plates and/or crude pieces of slag. Because of their great strength, slag elementals tend to be employed by ogreshaman. However, they seem to be very unstable and have been seen turning on their masters.
Due to Gordawg's absence from the Throne of the Elements, the Elemental Plateau has grown unstable, causing the elemental spirits there to devolve and mutate, where normally the elements live in purity. This has caused elementals consisting of both earth and fire to appear. So long as an earthen fury is absent from the throne, the imbalance in the elements will worsen.