This one took a sweet time to figure it out. My CPU barely managed to survive my experimentations with nodes, displacements and volumetrics. However, GPU handled everything else just fine, and I can't wait for 2.7 to have volumetrics enabled in GPU mode.
It is supposed to be a cloud mass of waxy smoke or something, but since I couldn't preserve the solid-ness of the mouth, I scrapped the idea of using a full volumetric cloud with scattering (too transparent). Since there is not fire/smoke sim in Cycles, I needed to make a work around with particles and a blackbody.
Digimon is (c) of Bandai & Akiyoshi Hongo
