Faerie Tale Theatre (1982)

S6E2 The Little Mermaid

After saving a human from drowning, Pam Dawber strikes a bargain with a sea witch to gain a human form. The witch grants her legs but warns that the prince must fall in love with her; if he doesn't, she will become sea foam for eternity. In addition, the witch steals her voice and informs her that each step will be painfully sharp, like walking on blades. Undeterred by these challenges, the little mermaid is determined to pursue her desires, regardless of the obstacles she faces!