What is the slimy, waxy covering that protects bacteria called?

The slimy, waxy covering that protects bacteria is known as a capsule. Capsules are typically composed of polysaccharides or proteins and serve several important functions for bacteria. They play a crucial role in protecting bacteria from desiccation (drying out) and can help the organism evade the host's immune system by inhibiting phagocytosis—the process by which immune cells engulf and destroy pathogens. Additionally, capsules can aid in adherence to surfaces, enhancing bacterial colonization. This protective feature is essential in the pathogenicity of many bacteria, as it contributes to their ability to cause disease.

Other options such as spores and prions refer to different biological structures or entities. Spores are a dormant form of bacteria that can withstand extreme environmental conditions, while prions are infectious agents composed of protein, associated with specific neurodegenerative diseases. Thus, they do not serve the function of a protective covering for bacteria, making the capsule the correct choice in this context.