The dissertation explores the complex structure of transmedial universes, which are the most prevalent and pervasive model in contemporary popular culture, and examines them within an interdisciplinary framework. In the chapter on the theoretical background of the research, in addition to general theories of adaptation, certain notions of media theory and transmedial narratology are included as well. Furthermore, as the title of the dissertation already indicates, the genre of the primary sources makes it necessary to incorporate relevant theories from the field of fairy tale studies as well, especially those referencing and relevant for the discussion of the story of “Little Red Riding Hood” in particular. The notion of transmedial microcosm used in this dissertation combines and complements Henry Jenkins’s and Jan-NoĂ«l Thon’s theories with Cristina Bacchilega’s conception of the fairy-tale web. Transmedial microcosms thus designate and delineate specific groups of adaptations that are based on the same source text and recount narratives set within a shared storyworld, yet they are markedly distinct from other transmedial microcosms relying on the same source text. The dissertation analyzes five distinct groups of adaptations that can be understood as transmedial microcosms from within the transmedial universe of “Little Red Riding Hood.”