Below Deck
A ship is raided by pirates. They open the way to the lower interior to find something that, to them, seemed like maybe a mummy. They thought it was cargo, so only one went down to retrieve it while the others fought off the more rowdy passengers. The "mummy" adjusted its hat. The lone pirate thought it was a trick of the eye. Then the thing stood up. It moved as if it was having trouble staying balanced, no it wasn't just that, it was like its body could scarcely support its own weight. Its arms and head seemed to be losing the fight with gravity, but its one visible eye was fixed on the intruder, and it somehow was slowly making its way forward.
The pirate would be screaming, but he was in disbelief of what he was witnessing. Surely this thing, be it corpse or prop, wasn't actually walking. Maybe it was that it already appeared mostly dead already and the pirate, sizing up, could probably take it on just based on physique, and just had to get over his opponent's strangeness before fighting it. But it's movements, so confident, even in this seemingly woeful, feeble state. The sway to its mesmerizing gait was diverting his attention to the situation. No, no, these were just excuses. He was just scared. Paralyzed by fear of this supernatural entity on an otherwise apparently average ship. As it staggered closer, the pirate smelled what he would attribute to the very scent of death itself.
Adrenaline finally kicked in and he reached for his sword. He stabbed right into the creature, and it fell limp over the blade. The pirate sighed, relieved ... for about half a second. Then the monster lifted its arm and gently brushed his face, its head still down. He heard a sort of gurgling noise coming from the wretched thing. Was it dying? Oh, no. No. No it wasn't. It was trying to speak. Once he realised this, the pirate ran by the sounds again in his head to try to understand what it was telling him. Despite its appearance, it didn't seem to be cursing him. On the contrary.
"... I'm so sorry about this ..." Do what now? He felt something warm and wet on his hand, but it was an awful lot and much too thick to be blood. It seemed as though the entirety of the creature was pouring out of the wound. The thing lightly gripped his shoulder for a brief moment, but it was collapsing from the top down. He tried to get away, but it was too late. The putrid black warmth was spreading and began to burn. Not a burn akin to fire, but acid. Putting his pride aside, he shrieked. He heard heavy footsteps as he fell over. The one to answer his call wasn't his crew. It was the apparent first mate of the ship he intended to raid. She stopped when she saw them and let out a small gasp; not of fear so much as surprise.