In the middle Interplanetary Age GeneTek, responding to the popularity of the small number of rianth somatic modification kits, launched a wide ranging program to produce augmentation packages offering consumers the ability to adopt traits of common Terran animals. As part of this range the Lepusans, also known as "Bunnies", were created. Several variants were developed over time with most focusing on changes to the head and legs whilst leaving the internal organs and torso relatively unchanged (aside from body fur). The augmentations were applied through a combination of autosurgical procedures, tissue grafts, cell therapies and somatic gengineering. Changes to user's bodies included adding a short tail, moving the ears and associated tissues further up the head as well as elongating them, altering the face and jaw to create a muzzle (often accompanied by engineering of the nose muscles and nerves to grant increased prehensile capabilities and involuntary twitching in response to emotional state) and significant re-engineering of the legs featuring extended metatarsals and phalanges which, along with motor cortex edits, replacing the normal human gait with hopping.
Population numbers steadily rose with Lepusans becoming a common sight in rianth heavy habitats, particularly those with low spin rates or on moons where the Lepusian legs were a great advantage in lower gravity. During the Technocalypse the nascent clade managed to survive in the Oort cloud where they co-habited with Kupierists and Haloists. There they fitted in with the splice, provolve, tweak, and hider cultures that flourished in their isolated habitats during that time. Even before the rise of the First Federation the original Lepusan stock had given rise to a number of new species and subspecies as different habitats drifted in the extent and type of bioaugmentation used. Some populations added augmentations to their clade template to become more akin to a natural rabbits (in one particular case adopting a set of digestive modifications that resulted in highly nitrogenated droppings to replace failing ecological infrastructure previously used for soil nitration maintenance). Other groups developed features modeled on fictional or mythological representations of rabbits, such as the Nippon-derived "Luna-Lagos" who were adapted to survive on a monodiet of gengineered rice. To varying degrees most groups adjusted their cognitive and social functions, partly in a response to their isolated environments and partly to continue the general rianth ideology of blending human and animal for mutually beneficial traits. Upon the founding of the First Federation some of the Oort cloud habs joined up, at first this resulted in a population decline as trade with and exposure to other cultures saw the Lepusan template outcompeted by more exciting clade forms. However this left a core of sophonts strongly tied to their clade and with the help of Federation scientific advances managed, as many early clade's did, to take their augmentations beyond merely somatic and into the germline.
While some Lepusans migrated to Dionysos, especially at the height of the Erotocracy, and other clades and "Warrens" (Lepus Clans and Houses) eventually joined the Zoeific Biopolity or the Utopia Sphere, most remained in Solsys. A convergence of traits engineered a familial and placid culture that discouraged individuals leaving their kin groups. Certain groups pushed their neuro-engineering for docility too far leading to a few notable periods where malicious groups were able to exploit those habs for economic or political gain. Notoriously the NoCoZo world of Atlantis developed a practice of forcing the template upon delinquent debtors in order to create easy-to-manipulate indentured servants (in one gruesome case a group was persuaded to run around an arena chased by engineered wolves for spectator entertainment). This misuse of the template was ended by the S1 entity GoodUrth who, in 6921, used their market power (and well provisioned personal security firm) to ruin the reputation metrics of anyone involved with the practice.
In the current era Lepusans are found throughout much of the Civilized Galaxy, although their greatest concentrations can be found in two highly populated systems of the Utopia Sphere and Zoefic Biopolity. A few non-affiliated Lepusan dominated polities exist (three encompassing multiple systems) though each with population numbers in the low billions.
The common clade template has lost some diversity in the latter half of the millennium due to an uptick in cross-culture migration. Currently the average Lepusan is shorter than human baseline at 1.5 to 1.6 meters, with a sturdy build and muscular legs. Although their eyesight tends to be poor, the other senses are highly developed. The body is covered in a short thick usually grayish fur and contrary to previous preferences large floppy ears are in vogue. Similar to their animal cousins Lepusan's experience strong pair bonding, though most variants of the clade have tweaked this feature to naturally cycle (and, though pheremonal control, sync between bond mates) creating a strong preference for serial monogamy that is predisposed to amicably end over 3-5 years. The total number of Lepusans of all species and subspecies in the galaxy today is estimated at approximately half a trillion.