Hi so I got sent something by magical sack, but I don't think I won a gm event. Why did I get stuff sent to me?

Scorpio's prize for sketch.io thing. Look at his signature.

He doesn't have a sig

Scroll down his profile page. I don't know why it doesn't appear under his posts.

In the options below the post box, there's a show signature button. He most likely un-checked it.