It's just called a capsule.
The outer covering of bacteria is called the cell wall. It provides structure and protection to the bacterial cell and is made up of different components depending on the type of bacteria, such as peptidoglycan in most bacteria.
capsule
They have shells to protect them from their enemies.
the capsule (outer covering of the bacteria)
The outer covering of fungal cells is called a cell wall. It is composed of chitin, a structural polysaccharide that provides strength and rigidity to the cell. The cell wall helps protect the fungal cell from environmental stresses and provides shape and support to the cell.
A stiff outer covering is often referred to as an exoskeleton, which is a rigid external covering found in some animal species, such as insects and crustaceans. This protective structure provides support, protection, and attachment points for muscles.
Conjugate - certain bacteria have polysaccharide outer coats that are poorly immunogenic. By linking these outer coats to proteins (e.g. toxins), the immune system can be led to recognize the polysaccharide as if it were a protein antigen. This approach is used in the Haemophilus influenzae type B vaccine. [Wikipedia]
what is seahorse outer-covering
The outer covering of the eyeball is cornea.
Amphibians do not have outer covering.
Bat is a mammal, so it's outer covering is hair whereas bird's outer covering is feather.
An exoskeleton is a hard outer shell or protective covering found on the outside of certain animals, such as insects and crustaceans. It provides support and protection for the animal's body and organs.