An apex consumer, or apex predator, occupies the highest trophic level in a food chain and has no natural predators. Food chains typically progress from producers to primary consumers, then to secondary and tertiary consumers, with apex consumers at the top. In the given options the grasshopper is a primary consumer feeding on plants, the frog is a secondary consumer feeding on insects, the snake is a tertiary consumer feeding on frogs, and the eagle feeds on snakes and other animals but is not typically preyed upon, placing it at the apex. Therefore the eagle is the apex consumer.