Hi, I notice you've asked an incomplete/unclear question. However, I inferred you want an example of a unicellular organism.
Answer:
Amoebas, Plankton, Bacteria
Explanation:
Remember, a unicellular organism is an organism (any life form) that has just a single cell. In other words, unlike humans/animals that have and regenerate millions of cells, a unicellular organism survives by means of a  single cell.
Amoebas, Plankton, and Bacteria are common examples of single-cell life forms. In the case of Amoebas, this single-cell structure enables the organism not to maintain a distinct shape; and so it can easily change its shape.