Miguzi was a one-an-a-half hour cartoon block that premiered on April 19, 2004, replacing Toonami's afternoon block aimed towards younger children. The block was produced by Williams Street, which also produces the late-night adult-oriented channel skein Adult Swim, as well as Toonami. The block was themed around Erin, a young girl who finds refuge within the confines of a strange spaceship that is trapped underwater and inhabited by aquatic creatures. She does not live in the ship, but comes to visit the creatures from above water.