Wosu (or Tinsuits) are wolf-like humanoids that reside on Hyrule. They are based on the enemy of the same name from Zelda II: The Adventure of Link.
Kevin, Link, Princess Zelda, and Gameboy were charged by three Wosu as they entered Parapa Palace. Link quickly destroyed all three with beams from his sword.
The Zelda Wiki states that "Tinsuit" is not a proper name for these creatures - it is actually the name of a different monster from the The Legend of Zelda cartoon.