Where did Michelangelo include a self-portrait in the Last judgment?

In the center of the painting is Jesus himself, who decides if half the human race joins him in Heaven, or must be sentenced to Hell for the rest of their afterlife. A lot of people are typically confused by The Last Judgment because of the fact that there is a lot going on at the same time. If looked closely, the top half represents those who are saints, angels and those who will go to Heaven, while the bottom still has those who are being resurrected or going to Hell on a boat led by a demon. All in all, this has to be the most complex painting Michelangelo has ever made.