I am looking for an old German story that talks about a boy called Mutchi, who lives many adventures. The problem is I don't remember many details about the story. I know he takes a ride with a fish to get to the bottom of the ocean , he travels with an eagle through the sky, and then the night comes (and it is a woman dressed in black) and he starts asking for his mum. Soon after that the boy wakes up behind a bush and realises he had been dreaming all along. This is all I can remember. I really wanted to find this book for my grandma cause her mother used to read it to her ( in German, from a German book with children's stories). This took place in the early forties, so that means the book has got to be older than that. Anyone at all who can help me with that?
The character sequence "tch" is rarely found in German words. The sound that English speakers would probably denote this way would rather be transcribed "tsch". So I changed Mutchi to Mutschi, and googling for "Mutschi Junge" I very quickly found the book Aus jüdischer Seele. Ausgewählte Werke, which looks like it contains a story matching your description. Unfortunately, I cannot tell the title from the Google Books excerpt.
Credits go to Loong for being smart enough to browse the book's table of contents and finding a nicely illustrated PDF version of the same story, which is by Jakob Loewenberg and is simply called "Mutschi".