From All the Badges of DEF CON 26 (vol 4) on Hackaday:
Hackaday Alum Sarah Petkus has been on a long quest to build an awesome robot with a lot of personality lovingly known as Noodle (check out her Hackaday Supercon talk on the adorable quadruped). For DC26 she decided to throw a con inside the con for Noodle and this is the badge.
Anyone following Sarah’s work knows that her art is on point and here is a great example. Look at the solder mask on front and rear and you’ll notice the lettering is mirrored. This gives it the appearance that this is a design you can see through the board. The bold use of patches of silk screen and gold-plated copper deliver her aesthetic boldly and make you just want to stare at the design. There is a little squiggle through the C on the front that is a superb touch! Driven by an ATmega328 and a CR2032, there are 10 LEDs on the back that flash for a backlight effect.