Fight Instructor reported a UAS in the traffic pattern caused near midair collisions with two training aircraft.

Narrative

Earlier today at approximately XA37 Zulu; I witnessed what looked to be a near midair collision (NMAC) between a C172 and an unidentified drone and then I experienced an NMAC with the same drone. The drone was a fairly large dark colored drone. I am unable to provide exact details as I was just focused on maneuvering to avoid it in the moment and I am therefore unaware of the type or exact configuration; but it was large and dark in color with working lights that were on at the time of the event. I was on downwind for runway XX at ZZZ approximately abeam taxiway 1 at 1800 ft. MSL when I witnessed the large drone nearly miss the 172 (multiple hundred feet lower than us) on left base for Runway XX. It was an unsettling moment as from my position the drone looked to be another plane. The drone was so close to the aircraft that I thought they were going to collide. The drone looked to have passed just under the aircraft. Just shortly after that event as it approached our aircraft (also a C172) I realized it was not a plane but rather a large drone flying from base to downwind (against the traffic pattern) at the same altitude as ourselves (1800 ft. MSL). The drone was directly in front of our aircraft at 1800 ft. MSL (where we were) and it was flying at us. I quickly took the controls and did a steep turn to the right to avoid the drone and we did not impact; however; it was certainly close and unsettling with a high chance for an impact and possibly poor outcome. Of course; I hope this was an unintentional mistake by the operator of the drone; but realistically it seems unlikely that you would accidentally fly your drone directly at two aircraft at differing altitudes and differing locations within one minute of each other.I reported the drone to local traffic on the CTAF immediately following the event for their awareness; and I was informed upon landing that the manager in the FBO promptly called the local police who were responding. I am unaware of what ended up happening with the police.Additionally; after landing I called ZZZ Approach and alerted them to the event and provided details. I submitted a safety report as well and a NASA ASRS report.