Hag fish fiber is a material scientists are conducting researching on. These strong fibers are found in the slime produced by the hag fish. It has a potential to compete with spider silk because it is easier to make.
Example Usage of fiber
johnbres: Nothing like rain and a fiber bar to keep your morning moving strong
money2ways: New post: High fiber Low Carb Foods - Important Things To Consider (http://cli.gs/hSqge)
knittingpatch: @julz91 thankfully, I've been lucky with that one - they've been great to the point they know to get the yarn/fiber to me quickly :-)