Genemorphs

He had no idea how long he had stayed like that, bent forward against the wind, before he became aware of someone staring at him. At first Sylvain thought his eyes were deceiving him: it was a catboy, straight out of a manga, complete with mobile triangular ears and a fuzzy tail that flicked nervously behind him as he squatted, looking up at the young man with yellow eyes sporting vertical pupils. The eyes of a prey animal ready to pounce.

Sylvain's hand darted instinctively towards his sidearm. But he didn't have the time to point it. With a blindingly fast motion, the catboy swiped at his wrist, leaving behind four parallel gashes.

— Distant Encounters

The first extrasolar colonies were well-established by the time medical science figured out how to tweak a living being's genetic code on the go without harming them. It took even longer for the procedure to become popular. Early adopters were again spacers and pioneers, who could be stuck for years far away from civilization, and/or in extreme environments (as Terraforming takes time, and seldom yields friendly worlds -- more like barely habitable, usually).
Baseline humans can become 'morphs in a matter of months, under strict medical supervision, which is necessary to avoid system shock and death. The optimal age to undergo the treatment is in the early twenties. It's technically possible to reverse the changes later, but it puts so much stress on the patient it's not recommended, except soon after a lengthy regen treatment and measures taken to fortify the body.
Genemorphs are the most varied brand of transhuman, but typically they exhibit superhuman stamina, pain resistance and even strength, in addition to healing easily from injuries. Since these abilities derive from genetic changes, and genes tend to have multiple uses, genemorphs also exhibit animal-like traits such as horns, tails, mobile ears or even fur. These can vary from mostly cosmetic to massive changes. In fact, genemorphs are divided into "light" and "heavy" by whether they can still have children with baseline humans or not.
Either way, genemorphs have rapid metabolisms and need massive calorie intake, even if they don't exert themselves. That also shortens their natural lifespans, so they need regen treatments more often.
Once notable exception are dragons, a morph type designed with the express purpose of surviving direct exposure to raw magic, which is otherwise lethal (see Sorcerers). That makes the gene pack popular among wizards. Unlike most genemorphs, dragons have slower metabolism and are naturally long-lived. However, they can't usually fly without assistance, their vestigial wing membranes being good for slowing down falls at best.
Numerous other standard gene packs have been developed, and custom morphs are possible as well.

Genetic Ancestor(s)

• Transhumans