My wife is a Finn, so I was introduced to Muumi on my first visit with her family in Kausala (between Lahti and Kouvola). Although, I am not familiar with the stories, so I don't know who Snusmumriken is.

As I have colorfully related to Havard already, when I was probably ten years old, I watched an anime episode of the Mummies (?),
where the boy Muumi jumped off a lighthouse's balcony and apparently drowned.

Had nightmares about it for years.