Neo-Mitochondrial Creatures, sometimes called Neo-Mitochondrion Creatures, or NMCs for short, are enemies found in Parasite Eve and Parasite Eve II. NMCs serve as the series main antagonists and "cannon fodder", each providing different means of attack, defense and styles. NMCs are encountered by the player very frequently to assist in leveling up Aya Brea's stats and provisions, and increase steadily in power and other offensive capabilities as the difficulty settings rise. At the beginning of the games, Aya is faced with more commonplace NMCs such as snakes and rats, but encounters more complex organisms as the game nears its climax, such as reanimated dinosaurs.