honestly I didn't think about exact measurements yet but he's definitely long enough to go boa constrictor on a tall adult and still have a lil bit of tail left 🤔

and he isn't patterned like a traditional mermaid with a distinct diff between humanoid upper half and piscine lower half; his skin is gray all over with a mottled and partially reticulated pattern. he's paler on the underside up to his face and darker on top as well! :D