I work at sfo airport. i injured my feet, so i was on day-shift "light duty" (watching a dumpster and recording trash drop-offs. sucks, but what can you do, right?) well, i was sitting at the courtyard 4 loading dock, facing outward toward courtyard 4. i was watching the clouds to see what the weather would be like that day, when a small craft approximately 15 feet wide and 25 feet long made a left-hand arc which started when i first saw it over the central plant cooling towers (at the domestic parking garage), making a left-hand arc over the roadway and courtyard 4, ending when it went over the building directly overhead of courtyard 4. it couldn't have been more than 20 feet above the itb (international terminal) roof. the craft was nearly black and uniform in color, with a slightly lighter colored canopy that was far too small for any person to fit. it had no lights, and no markings. at the front of the craft, it looked like a regular airplane fuselage, but it didn't have wings. it had short "wing stubs" on each side of the fuselage at the front, those sections were only ~4 feet long each. at the ends, they wrapped downward to form vertical "pods" ~4 feet in height and ~2 feet wide each. in the center-front of the craft was a similar pod, ~3 feet in height. at the rear of the craft were two additional vertical pods, one on each side with shorter ~2 foot "wing stubs". these pods were ~3 feet in height and ~2 feet wide. all the pods were rounded on the bottom. the craft made a jet sound, but not very loud. i heard the doppler-shifted jet sound for ~15 seconds after the craft was out of sight. my first thought upon seeing it was "what the @*!& is that?", then i looked around at the people smoking cigarettes (the smoking pad used to be at the courtyard 4 loading dock, but they moved it around the corner outside recently) to see if anyone else had seen it… apparently none had, then i thought "how did that thing fly with no wings?" my next thought was to call control and ask if there were any drones flying in the area… but then i thought, "that thing didn't have any markings or lights, and it was flying in an active airport airspace… and it didn't have any wings… i'm not touching that with a 10 foot pole." i'd draw the thing, but i lack any artistic ability whatsoever. i've searched online for drones that match, but found nothing even close.