It's a purple panda because I am a purple panda.
No seriously, once I came up with my pen name, I knew I wanted a kind of chibi image to be the face of it, especially an animal. I got the idea from a gamer I follow named Cryaotic whose "face" is an extreme close up of a cartoon boy's face or just a white mask on a man's face in fan art and stuff. So for me, bear or jaguar were my top choices, but all the images I searched for were ferocious, muscled up, and "bad-ass" which is the complete opposite of me, a 5' nothing furby of a lady. Then I saw this vector image of a weirdly shaped panda with no mouth on a sort of bland purple background and immediately felt like "yup, that's me, there's my whole being summed up in a single image." lol It was (in Robert Barone voice) "meant to be."