The Little Mermaid has a lot of LEGO Disney minifigures
LEGO Disney Princess Ursula - Minifig only Entry Minifigure - Walmart.com
Amazon.com: LEGO Disney The Little Mermaid Story Book 43213 Fun Playset with Ariel, Prince Eric, and Ursula Micro-Doll, Disney Princess Toy, Birthday Present for Kids and Fans Aged 5 and up :
Ursula • Lego Block Character – Ruffles in the Mud