The skeletons were the disguises of Duncan Grimm's henchmen.
Physical appearances[]
They were three skeletons of various heights, each of them wore a colored beanie, belts and torn clothes, two of them have facial hair and they each held a different blade weapon.
History[]
Scooby-Doo! Beginner Mysteries[]
The skeletons were supposed members of Angus Grimm's crew when the statue at the front of the boat seemingly came to life and attacked.
The three undead pirates assisted the living statue of Angus Grimm when they tried to scare away the gang, along with Greg Hibbard, the one who bought the ship, so they could reclaim it. They escaped being trapped in a net, and later caught everyone in a separate one, but they two got out and everyone fought on deck in a sword duel, and they were all knocked onto a lifeboat and nearly scared about being submerged when one of the Mystery Inc. members joked about dropping a cannonball onto the boat.
Duncan's crew unmasked.
The skeletons, along with the living statue all gave in and revealed they were all people in disguises. They were hired henchmen who were assisting the great grandson of infamous pirate, Angus Grimm, who felt ashamed of the family name being used for a museum that Greg was planning on opening, so they used black light effects on the boats sails to hide the black parts around the bones to make them look like convincing skeletons to prevent Greg from letting it happen.
Everyone left the crooks stranded on the boat so authorities could pick them up.