Unless you think a ghost is a "legendary creature", there are no legendary creatures which are in the cast list or appear on stage in the play. Legendary creatures are referred to from time to time in the text, as "as was to this Hyperion to a satyr".
No, you cannot create a token copy of a legendary creature in a game.
Yes, it is permissible to include more than one legendary creature in a deck, but you can only have one of each legendary creature on the battlefield at a time.
Yes, in Magic: The Gathering, you can copy a legendary creature, but if you have two or more of the same legendary creature on the battlefield, you must choose one to keep and put the rest into the graveyard.
Yes, in some card games like Magic: The Gathering, you can create a token copy of a legendary creature and use it in gameplay, but you can only have one copy of that legendary creature on the battlefield at a time.
Zambia!
In Magic: The Gathering, you can copy a legendary creature, but if you have two or more of the same legendary creature on the battlefield, you must choose one to keep and put the rest into the graveyard. This is a rule to prevent players from having multiple copies of the same legendary creature, as they are considered unique.
Maurice Abiteboul has written: 'Qui est Hamlet' -- subject(s): Hamlet (Legendary character)
raquaza
The Blue Hamlet (Hypoplectrus Gemma) is a small grouper native to South Florida, the Bahamas, and Belize.
Simona Draghici has written: 'Hamlet or Hecuba' -- subject(s): Hamlet (Legendary character), Tragedy 'The Pauper'
... it would be easier to answer if we knew who "they" are.
Manticore.