The following footage was submitted to YouTube channel Mrmb333 and was shot by an amateur photographer taken a video of the Moon on December 21, 2018.
While filming the full Moon a huge dark object comes into view crossing the moon without changing speed. It looks like it flies slightly behind the Moon at the top.
A remarkable detail; the full Moon occurred at the first day of the winter solstice late Friday afternoon and coincides with the Ursids meteor shower which is visible between December 17 and 25, 2018. A full moon coincides with the first day of winter solistice is a unique event given that the next time a full moon lines up with the winter solstice will be 2094.
The next footage shows the dark circular object at the moment it crosses the moon at the first day of the winter solstice.