The organism that eats the producer in a food chain is called a primary consumer.

Here's a simple breakdown:

* Producers: These are organisms like plants that make their own food through photosynthesis.

* Primary Consumers: These are herbivores that eat the producers. Examples include rabbits, deer, and caterpillars.

* Secondary Consumers: These are carnivores or omnivores that eat the primary consumers. Examples include foxes, snakes, and birds.

So, in a food chain, the primary consumer is the link between the producers and the rest of the food chain.