Pittacus is a member of Those Who Slither in the Dark, appearing in the map Stand Strong at Shambhala. It can be inferred that she wields some degree of authority in the organization, as she functions similar to other enemy generals. Defeating her will disable the two Viskam on the map.
Nothing is known about Pittacus' personality as she has no dialog and does not appear in any cutscenes.
Pittacus was an ancient Mytilenaen military general and one of the Seven Sages of Greece.