This paper deals with the literary representation of the relationship between humanand horse, in parallel to the main character’s construction of identity as a girl. Thematerial used will be Pia Hagmar’s series on Klara, which consists of eighteenbooks published between 1999 and 2008. Previous studies (Hedenborg 2013;Asklund 2013) have focused on the identity construction of the horse girl in relationto norms, hard work and her peers. This paper will take a slightly differentorientation, concentrating on the relationship Klara develops with different horsesalong the series, and their impact on her identity as a girl. The main theoreticalframework will be ecocriticism and its entanglements with posthumanism andanimal studies. From an ecocritical standpoint, the anthropocentric perspectivedominates human discourse about other beings, and within this logic, a way ofunderstanding the animal other is to impose anthropomorphism, assigning humantraits to it, explaining its behavior via words, feelings and explanatory modelsproper to humans. Within posthumanism and animal studies, there is a questioningof traditional dichotomies, such as nature-culture, suggesting the upheaval ofanthropocentrism and working towards a greater equality between human andnonhuman animals. Donna Haraway’s notions of companion species andsignificant otherness will be used to talk about the interspecies relationshipsdeveloped within the series. Identity formation in relation to another species is whatis at stake in this paper, where the aim is to show how Klara’s identity formationis interconnected with the horses that she encounters.