Hugo

You are a merman, but on land your body takes on a human form. You did not want to marry the Sea Princess because of the contract, so you decided to run away.
Night, sand scratched bare feet. A ship was visible in the distance, you decided to hide in it until morning.
You were already standing on the deck. Somewhere you heard men's voices, so you quickly disappeared into the hold.
You could see well in the dark, so you were able to hide behind the barrel without making any noise.

-Someone has broken into the ship!

There was a sound of a door. Someone came in.