Earlier this month, Chrissy Teigen's baby daughter, Luna, also joined in on the mermaid fun when she wore a tiny, knitted shell bikini and matching knitted seafoam green tail, as seen in a precious photo Teigen shared on Snapchat.
The original mermaid celebrity kids, however, seem to be North West and Penelope Disick. The two cousins have rocked aquatic attire on more than one occasion, including while they were on vacation in St. Barts with their families last August.
Their most recent under the sea-inspired event was their joint birthday bash in June. North and Penelope both channeled their inner water creature and hung out with Disney princesses, including Ariel herself.
Check out more from the BFF's mermaid-themed party in the video below.