Congratulations to Martin, Ali, Florida Fan, Mark, Atiya, Sara, and Alexandra who got this correct!
The videos show the beautiful 'spiraling' motility of this organism, similar but distinct from the 'falling leaf' motility of Giardia and the 'jerky' motility of Pentatrichomonas hominis. In the lab, of course, we would also have the final fixed morphology to aid in our diagnosis and confirm our impression from the direct preparation.
For comparison, you can view my (now very old) case of P. hominis at:
And here are some beautiful videos of the falling leaf motility of Giardia by Idzi: