Those look like hydra to me. Mainly I’m basing it on how they are stuck to the glass. Look at your decor and plants, they’ll be all over those too. As well as in your filter. Like another person said, dog dewormer is what you need. Fenbendezole is what you are looking for. The catch is most come in powder form, and it doesn’t dissolve in water very well. So it’s good to make a liquid solution. Take 10oz of tank water, mix in 1/4-1/2 tsp of the powder, shake it till you can’t shake it anymore. Then dose that liquid 1oz per 10 gallons.