Vague details of a video and cartoon based on a same myth.

[Bowyer2]

I made this forum to ask everybody for help to find a myth that I saw on this site. I don't know if I saw it on endosomatophilia in woman or vore in media. I remember see it in both a game and animation based on a the myth from other country but I don't know the details of the myth. What I remember in game and animation is about a protagonist, who looks like a kid is flying across the ocean, where he encounter a giant woman. Not sure if she's a giant mermaid, snake woman or a octopus woman. What ever she was, she seem to live under the ocean and she eat the protagonist, but he manage to escape through her digestive tract.