Bio-Armor

There's Powered Armor, and then there's this, the Organic Technology equivalent.

Leaving aside the fact that you're essentially wrapping a living being around yourself, it often forms some sort of symbiotic connection with the wearer, often drawing nutrients from the wearer's blood. Needless to say that might have adverse side effects. An even worse version might be sentient, and capable of taking over.

Might be worn by a Heroic Host. Subtrope of Organic Technology. Compare Living Weapon, a creature used as a weapon; and Living Clothes, clothing that has a mind of its own, though it may not necessarily be an actual organism in itself.


Examples:

Anime and Manga
  • Guyver is a classic anime and manga series about a high-school kid who gets his hand on a powerful set of technorganic armor that enhances the capabilities of its host and has to fight monsters called Zoanoids. The armor is virtually indestructible, and is able to regenerate from pretty much any wound, its only weak point being its Control Metal. As long as the Control Metal is intact, it can rebuild the host from the data stored within. But if it's critically damaged, the suit will eat the host alive.
  • Naruto: Obito, having survived being crushed by a massive boulder is Recuperating at the lair of the Big Bad. When told that his friends are in trouble, he uses Guruguru as Armor and allows him to do most of the fighting.

Comic Books
  • Marvel Comics: The alien symbiote race are basically this, bringing not just a new kind of a new suit, but enhanced strength and an armor to protect the user. Venom is the prime example, but also there're more symbiotes from the same planet as well some new entities created by the users (like Carnage and Anti-Venom).

Film
  • In Independence Day the small and physically frail aliens wear large and tentacled bio-suits that almost qualify as Mini-Mecha, though even then they can be knocked out by a sucker punch from Will Smith.

Literature
  • In the New Jedi Order series the Yuuzhan Vong wear "Vonduun crabs" as armor, which can stop blaster bolts and even lightsabers, but turned out to be fatally allergic to a type of tree pollen, which was later developed into a Synthetic Plague that could kill all Yuuzhan Vong and their "technology".
  • God-Emperor Leto Atreides II from the Dune series wears a full-body suit composed of living sand-trout, turning himself into an immortal human-sandworm hybrid. His only weakness is being immersed in water, which is what happens at the end of God-Emperor of Dune.

Tabletop Games
  • Living armor is one of Transcendent Technologies Inc's products in Hc Svnt Dracones. They allow their users to act like they have Reclamation surgeries, the TTI-Poltergeist even incorporates Transcendent tech, but if injured they have a habit of freaking out and sucking their users' blood.

Video Games
  • Sigma Star Saga: The Krill wear living armor called a Parasite, which despite the name are completely harmless, and even beneficial since they enhance the wearer's physical capabilities. Humans can wear them just fine as well with no negative side effects.

Web Original
  • AsteroidQuest bio-armors are scored by a "mortality rate" value, since stronger bio-armors put more strain on the user. In practice the actual fatalities are much lower, because soldiers are tested first and simply don't put on bio-armor if they can't take it.

Western Animation
  • On Adventure Time, Jake can sometimes warp himself around Finn and act as a suit of armor.
http://tvtropes.org/pmwiki/pmwiki.php/Main/BioArmor