When Octo Opus enters the battlefield, create a 4/4 blue Octopus Performer creature token named Contortionist with "At the beginning of your upkeep, you may fold this token in half." (It becomes 2/2, then 1/1. ½/½, ¼/¼, and so on.)

Sacrifice Octo Opus: Draw a card and an additional card for each of Contortionist's folds.