Euglena, a single-celled organism, is known for its unique structure and flexibility, lacking a rigid cell wall like plants. Instead, it has a pellicle composed of protein layers, which allows it to change shape and move. The pellicle in Euglena is a flexible, proteinaceous structure that supports the cell membrane and allows for shape changes.

Pellicles, which are flexible, protein-based structures found in Euglena, are not typically found in animals. Instead, animals have cell membranes and may have specialized outer layers like skin or exoskeletons, but not a pellicle. 

Pyrenoids are found in Euglena chloroplasts, but not in animal cells. 

Flagella are found in Euglena and some animal cells (specifically sperm cells), with Euglena using them for locomotion and animal sperm cells for movement. 

Paramylon granules, a storage form of carbohydrate similar to starch, are found in Euglena, but not in animals.