Well, to start off, I masked the person's body off using the pen tool. I saved that path for later. I then made a custom brush out of several characters from varying typefaces. I then went into the brush settings and randomized its scatter and size and drew the general funnel shape.
Then I selected the pixels of the person's path, and on a new layer brushed with the random brush.
Repeat this process with different custom type brushes and it pretty much makes itself.