However, the play is full of extraordinary anomalies and fantastic interludes, including Gonzalo's fantasy of a utopian commonwealth, Prospero's magical servant Ariel, and the "poisonous slave" Caliban. The creation of Caliban has particularly fascinated critics, who have noticed in his creation a colonial dimension to the play. In this respect Caliban can be seen as an American Indian or African slave, who articulates a particularly powerful strain of anti-colonial sentiment, telling Prospero that "this island's mine, by Sycorax my mother,/ Which thou tak'st from me". This has led to an intense reassessment of the play from a post-colonial perspective, as critics and historians have debated the extent to which the play endorses or criticises early English colonial expansion. --Jerry Brotton