Janus appears as a metallic, blue-tinted statue (a metallurgist may guess blued steel) of a hairless man, if that statue were dressed in the guarb of a roman military tribune, complete with breastplate, spatha (long sword), and plumed helmet. And if that statue could walk around and talk, which Janus certainly can, although he is also able to float in the air and move that way.

Janus preferred move a transportation, however, is his ability to open portals to near and distant places. Which is presumably why he took the name Janus, unless he really is the Roman god of the same name. Janus will never confirm nor deny this, insisting only that he should be called Janus. He otherwise remains silent about his origins.