Stentor, sometimes called trumpet animalcules, are a genus of filter-feeding ciliates. Stentors can reach lengths of two millimeters, and they are among the biggest known unicellular organisms. Their bodies are generally horn-shaped. A ring of cilia around the anterior “mouth” sweeps in food and aids in swimming.*

As is with many ciliates, Stentors filter feed. This means that they will eat just about anything that gets pulled in their direction.  Their normal diet includes algae and bacteria,  but they will also eat anything they can catch!

Stentors are commonly found in most freshwater ponds, attached to vegetation or other surfaces where they generally spend their lives. When necessary, they can detach and use their cilia to move to another location. While swimming, they assume an oval or pear shape.**
*Information from: Rachel; Stentor: https://rsscience.com/microscopic-organisms-pond-water/#Stentor
**Information from: Nikon - Microscopy U: Stentor (Protozoan) Videos: ​https://www.microscopyu.com/gallery-images/stentor-protozoan-videos