The Little Mermaid (1976)

The little mermaid rescues a prince from drowning and falls in love with him. To be with him, she makes a deal with the evil sorceress: her beautiful voice against a life on land. It seems to work at first, the prince is enchanted with her lovely appearance. But the memory of a foreign princess still haunts him: The one who found him on the beach where the mermaid had left him, and whom he (of course) believes to be his saviour. To resolve this mistake is too much for the mute little mermaid, and not even her father, king of all seas, can help her in the impending catastrophe.