Winnie is a pink and blue seahorse character appearing in the animated series based on Hans Christian Andersen's fairy tale. She acts as the steadfast companion to Marina, the mermaid protagonist. Unlike real seahorses, Winnie possesses two fantastical abilities: emitting piercing, high-pitched screams capable of rendering humans and other characters unconscious, and taking flight through the air when outside water. She employs these powers throughout the narrative to aid Marina and disrupt the plans of adversaries during conflicts.

Winnie's primary role involves supporting Marina's efforts to sustain a relationship with Prince Justin, the human prince, and thwarting schemes by antagonists like the sea witch Hedwig. She operates alongside allies such as Bobo the tropical fish and Ridley the sea otter, contributing to group endeavors aimed at overcoming obstacles. Demonstrating loyalty and courage, Winnie frequently engages directly in confrontations with Hedwig's forces, which include creatures like Dudley the hammerhead shark, Hugo the giant octopus, and armies of barracudas and sharks.

Information regarding Winnie's origin, familial background, or specific character development across the series' episodes or any supplemental media like movies, OVAs, or spin-offs is not available. The character remains defined by the established role, physical characteristics, and abilities throughout the depicted events.