Moomins are Finnish trolls, as Finnish is their author Tove Jansson (there are comics she wrote with her brother, but Moomin books are mainly novels). I think the first book came out in the late 40's or so.. so yes kupo, they definitely came out before you were a teenager
Japanese producers in the 80's made an anime about them though... partly based on the books partly not. They even made a theme park dedicated to Moomins in Japan. The anime is nice but the books are completely different thing... much more entertaining, a lot of humour, fantastic pieces of artworks as illustrations. I suggest you to get some of these books if you liked the anime. You'll like them even more
