Shall we start with the smaller one?
Other Large "sea serpents"...
Crested Sea Serpent: Str 17-23, Dex 14, Con 17-21, Int 8-10, Wis 13-15, Cha 16-18
Lantern Sea Serpent: Str 17-23, Dex 10, Con 17-21, Int 14-16, Wis 15-17, Cha 14-16
Spiked Sea Serpent: Str 17-25, Dex 12, Con 19-21, Int 6-8, Wis 15-17, Cha 14-16
Dragon Eel: Str 26, Dex 11, Con 21, Int 8, Wis 12, Cha 13