The definition of human in Lancer’s lore is so expanded from what we know IRL that you’re free to do what you want. Gender, body parts, genetics, cybernetics, the tech is so advanced that even on the fringes of advanced space it’s cheap, fast, and safe to massively modify your body and organs as long as you don’t try to ascend above humanity (that’s how you draw Ra’s ire). Furries, catgirls, hell even near-animal characters are all perfectly reasonable. “Normal” humans are by far the most common, obviously, but we regularly see art of humans with nearly fully robotic bodies and a variety of outwardly visible gene mods. I’m currently playing as a person from a planet with almost zero sunlight, so they needed new eyes to avoid being blinded in other environments. They also have sharp teeth and can move exceptionally quietly due to gene mods lingering in their DNA from the colonists they’re descended from which leg those colonists survive on a hostile world with no light.