Undead, better known as Zombies, are what's left of the dead bodies buried in the Caribbean. They are mostly risen by dark forces, and used for servants of the dreaded Pirate Blackbeard. In Lego Pirates of the Caribbean, Zombies are found aboard the Queen Anne's Revenge, with a very goofy personality, like most other Lego characters. They all possess super strength as one of their abilities, and can walk underwater.
They're very vicious in battle.
Zombies and Blackbeard