LEGO Duplo has featured sets based on Ariel from Disney's "The Little Mermaid," designed for younger children. These sets include larger bricks and simpler builds suitable for ages 2 and up. Notable sets include 10515 Ariel's Undersea Castle and 10922 Ariel's Underwater Symphony. These sets allow toddlers to recreate scenes from the movie with characters like Ariel, Flounder, and Sebastian, promoting imaginative play and early building skills.