The Queen Mary is or was a ship.
Description[]
The Queen Mary was, by 1957, known to Donald Duck and Yellow Beak as the biggest and most prestigious ship in the world. Both Peg-Leg Pete and the Beagle Boys posed as former sailors on the Queen Mary when trying to get themselves hired (in disguise) as crewmembers on Yellow Beak's ship during a treasure-seeking expedition. Yellow Beak obviously did not believed their claims, but thought they were simply self-aggrandizing sailors, and thus hired them anyway because he “liked their nerve”.
Behind the scenes[]
The Queen Mary was mentioned in the 1957 comic story The Treasure of Yellow Beak.
The RMS Queen Mary existed in real life and was indeed hugely prestigious. However, it only held the title of world's biggest ocean liner briefly, for a few weeks in 1936, before losing it to the French Normandie. It is unclear if this fact differs between the Prime Universe and the real world, or if Donald was simply misinformed (or exaggerating) when he mentioned it as “the biggest ship in the world”.