They can't protect themselves is the name of an exhibition intended to raise awareness about endangered marine species. From the project's mission statement:
"Marine life has several natural defenses such as speed, camouflage and schooling behavior. However, these defenses are powerless against man-made threats including pollution, ocean warming, and overindustrialization. To convey our need to protect these animals, this collection of life-size armor was born. Transcending cultural and regional boundaries, these artifacts are meant to inspire all to preserve the ocean and the myriad of creatures that call it home."
How about a race of intelligent, armoured dolphins for your world?
Or samurai cranes?