: A weapon which is a living organism.
- Straight: Bob uses a sword which is actually a type of plant. He can even leave it in the ground and have it grow into a sword tree (if he doesn't mind waiting several years).
- Exaggerated: Bob carries a gun which is actually a type of domesticated animal or symbiote which just happens to be able to function like a BFG.
- Justified: The people of Bob's homeworld's society sprung up (ha ha) around these plants, which they used to fight off the extremely hostile native fauna. In addition to having several advantages over normal, metal swords (such as being able to repair itself like any other living creature and secreting acid or biting enemies for extra damage) it's his cultural Weapon of Choice.
- Inverted: All weapons are mechanical, even Good Old Fisticuffs are avoided.
- Subverted: Bob discards his plant sword and picks up something better after finishing the tutorial level.
- Double Subverted: That something is a "mature" sword which was planted specifically for him to wield (as per their tradition) when he grew up, to replace the training sword he was using.
- Bob's sword constantly needs feeding, leading to Perpetual Poverty.
- Bob's sword is not only good as a weapon, but also good in playing video games.
- Zig Zagged: Sometimes it's just a wooden sword or sword shaped piece of fruit, other times it's still alive.
- Averted: Weapons are purpose-built devices or the natural weapons of the combatant.
- Enforced: Bob's created with a Nature Hero in mind as part of an Author Tract on the environment. They also use this trope to explain how he could have an Evolving Weapon (thus allowing them to make more toys) without advanced technology.
- Lampshaded: "Are you going to polish that or pet it?"
- Invoked: Alice, a member of a Benevolent Precursor race, genetically engineers the sword plant and seeds the world Bobs people colonized to give them a fighting chance.
- Exploited: ???
- Defied: Bob shuns weapons which aren't made from the ground up, arguing nature shouldn't be used to such ends.
- Discussed: "So his weapon's some sort of plant? How does that work?"
- Conversed: "Is that some sort of creature which you carry around as a weapon? BADASS!"
- Deconstructed: Bob's sword just isn't as good as metal swords and other advanced weapons; living creatures can't catch up with technology.
- Reconstructed: It turns out that sword plants are an Evolving Weapon. When Bob's backed into a corner, he gets his Mid-Season Upgrade.
- Played For Laughs: Bob's weapon acts like a pet dog, providing comic relief.
- Played For Drama: Bob's weapon falls ill, leaving him defenseless.
... just a moment... come on... okay, your link back to Living Weapon
has finished growing!