Hair is a fiber that is found only in mammals.
Hair has turned auburn red.
Something that can be auburn is a fiber found only in mammals.
What is a fiber found only in mammals?

  Something that can be auburn
  They have thick fur
  Something that is self-aware
  with their fur
  To keep their body heat.
  it helps plants in growing
  it keeps an organism warm
  Something that comes in a bundle of fibers