Yeah, I'd probably start with Dagon, boost Dex a little and reduce Con a little. Maybe Str 36, Dex 16, Con 34?
averaged that Str 37 dex 12 con 36. I would say his mental stats are closer to dagons with the exception of charisma which should be higher he is the leader of a cult.
I know dagon is as well But all he has to impress is fish. Hell i can do that with a jar of flakes and going here fishy fishy.
I'll update the Ythog-Nthlei Working Draft.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.