A young woman found a living sand dollar and recorded it. The clip went viral again this week.
The video, as the uploader notes, shows the “difference between a live and a dead sand dollar.”
https://www.youtube.com/watch?v=3uwOURjneWQ
A sand dollar is a type of burrowing sand urchin belonging to the order Clypeasteroida.
Their related animals include sea cucumbers, starfish, and sea urchins.
They have tiny spines all over their bodies that look like hair, and they help the animal move along the ocean floor.
In the clip, you can see the spines moving at around the 1-minute mark.
(H/T - Littlethings)