A leatherback is a selectively bred bearded dragon that's scales are extremely and uniformly reduced. My khan is a leatherback. You can see his photos on the link below my sig. The explanation I gave is a pretty simple one, however.
Here is a link that discusses the different genetic morphs seen on the beardie market in more detail, including leatherbacks: http://www.mbdragons.eu/en/genetica.html
Mirage came out of brumation on April 26. He was doing great. On May 2 he started acting funny. We just redid his tank, and he keeps going into one of his hides. He just lays there. He shows no intrest in food. HELP!