Little Mermaid Birthday birthday party supplies. The best girl's Birthday Party Ideas start with a great birthday party theme, so for a fantastic Disney Little Mermaid Birthday Party, start with our amazing selection of Disney Little Mermaid Birthday Party Supplies. Ariel as the Little Mermaid makes a great party theme idea for an amazing Birthday Party! Kid's just love Ariel. Have a party to remember this year with a mermaid girl's birthday party theme featuring Disney Little Mermaid! Great Birthday Parties start with Great Birthday Party Supplies!