Grey capsule‑shaped creature with long tail in canal

https://preview.redd.it/coxblftuzmkh1.png?width=1536&format=png&auto=webp&s=7cbe113b9647cd692d2d1190eeb1b6ae3e3bd3dd

I spotted a strange creature in a canal after laundry water with detergent was poured in. It’s about finger‑sized, grey in color, shaped like a capsule with a long tail. It moves in a caterpillar‑like way, lifting its body as it crawls/swims. It looks almost bacterial under the eye but is visible without a microscope. I haven’t found anything similar online and would love help identifying what this could be.