To quote just one interesting thing (for me):<p>"Hagfish slime is made of two different kinds of protein. One is a type of mucin, which acts much like the mucus that the human body uses to drown bacteria and viral intruders in antibodies and enzymes.<p>The other protein is in the form of tiny threads that are 100 times thinner than human hairs. These strong and stretchy threads act a lot like spider silk.<p>....<p>At any given time, a hagfish has about 20,000 km of fibers inside its body, ready to go"