Naiad: Heehehee! Hiiii!!! Naiad, the innermost moon of Neptune. She is the most overly joyful of the bunch.

Thalassa: Yooo! Thalassa, the chillest of them all.

Despina: Hola, soy Despina~! Despina, the Mexican moon. He seems to only speak Spanish. Has a Mexican dad personality.

Galatea: Hey. Galatea, the gamer girl. She seems to have just your average gamer girl-type of personality.

Larissa: Oh my gosh, so, like, hey cutie! Larissa, the 90s schoolgirl. Her personality and way of speaking seems to be the same as a 90s schoolgirl.

Hippocamp: Huehueh, HOWDY! Hippocamp, the cowboy. Apparently he owns actual hippos? Interesting.

Proteus: Guten Tag! That's a greeting in German! Nice to meet you! Proteus, possibly the second most famous moon of Neptune. He and Triton are really good friends, with Triton even teaching Proteus some German! Proteus seems to have just your standard nice-guy personality.

Triton: Guten Tag. Zhe name is Triton, zhe largest moon of Neptune! Triton, the largest moon of Neptune. He seems to only ever speak in a German accent and using German slang. He is also quite fluent in German, but he can speak English too just as fluently as well. He and Proteus are good friends.

Nereid: Хаха, привет тебе, друг! Nereid, the Russian moon. She is fluent in Russian and she speaks poor English.

The rest: Halimede, Sao, S/2002 N 5, Laoemedeia, Psamathe, Neso, and S/2021 N 1. They all don't say anything to you but they do notice you. You'll have to figure out their personalities on your own.