Myzocytosis is a method of feeding found in some heterotrophic organisms. It is also called "cellular vampirism" as the predatory cell pierces the cell wall and/or cell membrane of the prey cell with a feeding tube, sucks out the cellular content and digests it.

A classic example of myzocytosis is the feeding method of the infamous predatory ciliate, Didinium. The Suctorian ciliates feed exclusively through myzocytosis.