The correct term is "Hippo" or "Hippopotamus".

The name sprang out of a childish (and specificly Danish) joke: "The riverhorse has bad in the betweenfloor" - meaning approximately "Hippo´s got a stomach-ache".

Veeeery droll ! And, ultimately, the band had to have a name.

Later, we learned that there is a brewery in the USA by the same name. That´s OK. We don´t mind. They don´t mind either - or so we think.