Esox lucius, commonly known as the northern pike, is a freshwater fish found in North America, Europe, and Asia. It typically inhabits lakes, rivers, and marshes, preferring areas with abundant vegetation. The northern pike is recognized for its elongated body, sharp teeth, and distinctive greenish coloration with lighter spots. This species can grow quite large, often reaching lengths of 20 to 30 inches, although some individuals can exceed 40 inches. Esox lucius is a carnivorous predator, primarily feeding on smaller fish and invertebrates. Its swift movements and sharp eyesight make it an effective hunter in its aquatic environment.