Joerg,

I don't know why "mongoose" (which is a member of the civet family, native to India, semi-domesticated and kept for the purpose of killing venomous snakes)...

Except maybe the translator decided that the animal in question should be exotic, as the author of the webpage Mudgaurd posted suggested... And it certainly makes more sense as an exotic animal than a sea-slug, given the context of the story (As my dad pointed out, if you put 'Aplysia kurodai' on display in a public market stall, it wouldn't be a sea-slug for very long -- it would be a dead little puddle thing)...

But guinea (sea)pig works, too... it fulfills the exotic catagory (they are native to South America) they are smaller than a rabbit (weighing about a kilo at their largest), they are cute and cuddly (mongooses are famous for being viscious), and they like to climb on people.

So, here's the $64,000 question: How did the story #191 get the title "Das Meerhäschen", anyway?