Water people

Water People (ウォーターピープル, U~ōtāpīpuru) are a mysterious race of liquid creatures.

In Magical Vacation
They used to exist in the Plane of Water, but were driven out when Enigmas invaded their realm. This caused them to be flung across all kinds of planes, and those who ended up in the Plane of Darkness created Akvavit Castle.

Some Water People can also be found in parts of the Plane of Death, namely Moiroroto Village and the Corridor of Death. They wish to be reborn as new beings by passing through the Corridor.

The language that they speak is the Erimu Language (Aquarium in the fan translation). It's written in a gibberish blend of hiragana and katakana, and sentences close with a bubbling noise. The only way to understand what they're saying is by having Blueberry in your party, as she is fluent in Erimu.