Three Headed Dog was a version Lucid Puppy Linux (529) had the kernel 2.6.37.6 same as Slacko 531 to support newer hardware.  By Playdayz based on 5.2.8.

Original thread: http://www.murga-linux.com/puppy/viewtopic.php?t=70736

Richard Erwin did an update of it and other Lucids

http://www.murga-linux.com/puppy/viewtopic.php?t=90461