[Aaron] says in our comments that he also made an LED dog collar. This Christmas themed dog collar uses an ATTiny13a and a hand full of red and green LEDs (28?). While the animations aren’t as complex as the collar we posted earlier today, we though you might enjoy this one as well. From the description, we think that the LEDs simply fade back and forth between red and green. We think that [Aaron] did a great job. He has included the source code and schematic on his site, but sadly there’s no video of this collar in action.