Martians are a highly intelligent species native to the planet Mars. Calling them "Martians" as if they represent all inhabitants of Mars used to be controversial, but hasn't been a problem since they eradicated all other life forms on their planet (with the possible exception of unicellular organisms).

Thanks to their advances in space exploration and colonization, Martians are among the most prominent species in the Milky Way galaxy. They control many inhabited worlds, which are all considered to be part of a region called Ocelordia.

Martians are naturally an aquatic species, possessing one pair of limbs. Many of them are augmented with an artificial second pair that they use for movement on dry land. Some, known as "fouries", have gone as far as to genetically modify themselves to have a natural second pair of limbs.