I decided to recreate the beta Drowned texture seen in a development screenshot released by the devs. In the release of this pack I swapped around the arm and leg textures to better suit the original as well as added the three wide arms! (Optifine required)

If you have Optifine installed and prefer the beta drowned WITH four pixel wide arms, then delete the "drowned.jem" file found in "Classic Drowned > assets > minecraft > optifine"

I'm a bit new to all this, so if you encounter any bugs or have any requests/suggestions leave them in the comments.