The Little Mermaid Backpack and Lunch Bag - Bundle with 15” Ariel Backpack, Lunch Box, Water Bottle, Stickers, Tattoos | Little Mermaid Backpack for Kids. This Little Mermaid school bag set includes a 15” backpack with front pocket, features adjustable shoulder straps, zip closure compartment, and top loop for hanging featuring colorful artwork of Ariel and Flounder. The Little Mermaid back to school set also includes an insulated lunch bag featuring Ariel and Flounder, perfect for keeping your food safe to eat all day long.