Everypony else was doing it, I just wanted to be popular!
His name is Shadystep and is my ponysona. His appearance is based on my own - the hairstyle was simplified for the sake of my sanity - Curly hair is one of the most agonizing things to draw.
And the cutie mark doesn't mean anything, at least nothing I can explain in a timely manner. But I picked a symbol that would make it easy for me to characterize him if I ever decide to. Besides, it's cool.