League of Legends’ yordles live in a self-contained pocket within the spirit realm of Runeterra with no direct counterpart in the material realm. Most of them usually stay at a place called Bandle City inside the mystical realm and only some are leaving on rare occasions.
While it is highly unlikely for them to reach a body-height of more than a meter regardless of gender, the species tends to inhibit some gender specific features. Male specimens have fuzzy to bushy fur coating, while females are just slightly covered in fur most of the time. The little creatures have an extremely good sense of hearing, enabled by their foxlike ears. Plus, they can see infrared wavelengths of light with their large eyes that are otherwise inferior to human vision.
Magical traps made of material like runic iron, expose them to something like an electrical shock upon touch, paralyzing them and disabling their magical abilities, just as fans were able to observe in the recently released cinematic featuring Tristana, Lulu, Teemo and Corki. It is also known that our cuddly friends age differently than most other species living in Runeterra, with Poppy being over a thousand years old, not looking like an individual of that age at all. This could partly be described by their natural habitat located in the spirit realm, far away from concepts like progressing time.
A striking discovery in researching their evolution is Fizz, an amphibious subspecies from prehistoric times, when Runeterra was mostly covered by water and far away from modern civilization. Back in the day, the tiny fur balls supposedly had more animal-like features like tails and canine teeth, living as nomads in small family groups and near early humans. As human civilization advanced, they had to blend into the crowds, so they won’t scare people off with their rather unusual appearance.
Using a special way of cloaking magic called Glamour, they can take on the likelihood of small statue humans and sometimes almost becoming invisible to the untrained eye, subconsciously fading from the viewer’s notice.