Originally Posted by TheChiatroll
At first merglings were a different race then yordles and poppy didn't exist then. Merglings were then retconned into a specific group of yordles in trist's background. At this point Trist still looked different from the other yordle but she was female.
Latter they made a second female yordle named poppy. It is established the only other female yordle (yes yordle, because merglings being a race was retconned) looked different at this point when you look at trist and then teemo or heimer I suppose they just made the non furry purple mergling look a gender difference among yordles.
It isn't that strange of a gender difference really. less hair and different pigmentation. It's nothing as drastic and an angler fish.
Last I remember the explanation was Yordies was a gropu term covering many different sorts of creatures living together for a common goal. This group is composed of cute looking, short... stubby... things.
Teemo and Kennen share a related race(possibly), where as Heimer and Corki lack much in common. Poppy and Trist are alike, but nothing close to Heimer/Kennen/Teemo/Corki. And yes, Corki is a Yordie(Who isn't all furry).
And... who knows WTF Veigar is.