This article is about Selkie, the mythological seals who shed their skin to become human. You may be looking for Selkie a race from Winx Club cartoon.
Selkie by Carolyn Emerick 2013

A girl stepping out of her sealskin.

Selkies are a type of almost-mermaid creatures found in Irish and Scottish cultures. These seals can climb onto dry land and shed their sealskins to become humans. If you take their sealskins away, they cannot return to the sea and are stuck as humans.