A characteristically star-shaped type of glial cell found in the optic nerve, brain and spinal cord. They have many processes, giving them their star shape, which terminate in structures called end-feet. They are the most numerous glial cell in the central nervous system and can behave like phagocytes in the CNS during metamorphosis. [ http://purl.obolibrary.org/obo/CL_0000127 XAO:curators ]