Knights are the only playable race in Spiral Knights.
The Knights are vertebrates of organic structure, resembling short humanoids with dark skin, glowing eyes and stumpy feet. As organic creatures they can suffer from biological imperfection and sickness. They are warm-blooded, have hair, and wear clothes.
Knights can be affected by neurological disruption, are capable of emotions, have various personality traits including those of the anti-social deviation, and in some cases, most notably the Arkus incident, can be driven mad.
They take part in recreational activities, have short noses with a sense of smell and need to, or at least enjoy, eating and drinking; like most vertebrates, they utilize teeth to break down food before digesting it. Some armors and shields double as cooking apparatus, giving the impression that Knights possibly do not have the biological ability to eliminate harmful bacteria in foreign consumables. Knights have a sense of hearing and a sense of touch, with some armors designed with comfort in mind and others sacrificing comfort for maximum protection.
Knights do need to breathe although it is unknown what they breathe to survive, or if they can breathe the atmosphere of Cradle.
Although Knights are not fused permanently with their armor, they are never seen without it, and rarely without their weapons. Although knights (or possibly their armor) can carry an incredible amount of mass, they are still slowed down substantially when utilizing heavier armor and weaponry.
According to in-game lore, the Knights originate from the planet Isora. After an event (or series of events) named the Morai Wars their race was at the brink of extinction, having to leave the planet and search for a power source to save their homeworld, their commander being Ozlo. They roamed the galaxy in the Skylark before crashing to Cradle.