Secret Sauce Agent was a member of the Jack in the Box Bunch .
True to his name, he was constantly shrouded in shadows and hiding. He was apparently in charge of making secret sauce and zealously guarded its ingredients.
It is unknown if he was actually a secret agent working for a government agency in addition to his work for the Jack in the Box corporation.
In the comic books, he is depicted as a Caucasian male with a large nose, wearing a purple trenchcoat, black pants, and what appears to be a fedora hat. Some panels appear to imply he is bald under the hat. A bendy toy of Secret Sauce Agent features him with purple skin.
One depiction of him features him carrying a pot labeled "Secret Sauce" which does not seem conductive to secrecy.