Cylindria, often called Cyli for short, is one of the three main protagonists in the animated series Pac-Man and the Ghostly Adventures. She is a young Pac-Worlder, approximately thirteen to fourteen years old, who stands out for her vibrant pink complexion and distinctive fashion sense. Her black hair is styled into two pigtails with light pink highlights, secured with red bands, with two locks of hair often framing her left eye. She wears red glasses and a practical outfit consisting of black fingerless gloves, red and white striped socks, and black boots with silver buckles. Despite her youthful appearance, she is depicted as being only three and a half inches tall, a standard scale for characters from her world.

Within her friend group, Cylindria is widely recognized as the brains of the team. Her personality is defined by a blend of kindness, intelligence, and a strong sense of responsibility. She is often the first to notice when a situation seems suspicious and is not afraid to point out oversights, even if it means keeping her friends from making impulsive decisions like eating stolen food. This level-headedness makes her the most responsible member of her social circle, as she often acts as the voice of reason. Her bravery and heroic nature run deeper than her initially girly appearance might suggest, making her a surprisingly capable fighter when the situation calls for it.

Cylindria's personal history and motivations are closely tied to her relationships. She was formerly in a relationship with Skeebo, but the two broke up after he refused to rescue her from a Netherworld monster. This event likely solidified her preference for reliable friends over shallow popularity. Her primary role in the story is as a loyal ally to the hero, Pac-Man, and their mutual friend, Spiral. Together, the trio navigates the challenges of being teenagers while frequently banding together to protect their planet from ghostly threats. While she dedicates herself to helping Pac-Man fight ghosts like Lord Betrayus, her trust does not typically extend to ghosts in general, especially the ghost Pinky. This dynamic creates an interesting rivalry, as Pinky has a well-known crush on Pac-Man and views Cylindria, who once accidentally confessed affection for him, as a romantic rival.

Throughout the series, Cylindria remains a steadfast supporter of her friends. While there is a brief suggestion of a potential crush on Pac-Man, this plot point is largely fleeting and does not define her primary role as a supportive and heroic friend. Her development is less about personal change and more about the consistent application of her intelligence to solve problems. In the video game adaptations, her capabilities expand further; she is depicted as a playable character who uses a hoverboard to shoot at enemies, showcasing her agility and combat skills. Outside of combat, she is also noted for specializing in gymnastics, adding a layer of physical grace to her intellectual prowess.