Slime molds have characteristics of both molds and protozoa. Under certain conditions, the slime mold exists as masses of cytoplasm, similar to amoebae. It moves over rotting logs or leaves and feeds by phagocytosis. The amoeba stage is called the plasmodium, which has many nuclei.
The amoeba stage ends when the plasmodium matures or encounters a harsh environment. At this point, it moves to a light area and develops fruiting bodies that form spores at the ends of stalks. The spores are resistant to environmental excesses. They germinate when conditions are suitable to form flagellated swarm cells, or amoeboid cells, which later fuse to again form a multinucleate plasmodium.