I think so. It’s unlikely to have been a real bear, since they would have been too dangerous, so it would have been an actor dressed as a bear. Isn’t Yogi Bear a character? (Though of course he talks.)
How would Yorick be an essential character?
It could have been a real bear-- There was a bear-baiting place right next to the Globe, and they could surely have borrowed one that was sufficiently disabled/sedated/restrained for that one scene. Alternately, the one time I’ve seen the play, the bear itself wasn’t shown at all: We just got sound effects and the actor reacting (very effectively) to the unseen (by us) beast.
I concur that it could have been a real bear – these are, after all, the same people who thought a couple of years later that it would be a brilliant idea to shoot off cannon in a wooden theater with a thatched roof. Safety, pfft, who needs it? (I’ve also seen speculation that King James’s own personal polar bear might have been used for court performances, although this strikes me as much less likely; those suckers are mean.)
That said, I still maintain we should be thinking babies-and-corpses rather than bears.
I don’t think it matters whether it was a real bear or not.* The dog in Two Gentlemen of Verona is usually (but not always) played by a real dog, and I’d consider him a character. If the bear in A Winter’s Tale isn’t “really” a character I’d say it’s because it does so little in the play, not because it’s an animal, but the question calls for a character who does very little so that doesn’t help us here.
*FWIW, according to Wikipedia it’s not known whether the part of the bear in Shakespeare’s time was played by a live bear or a costumed actor.
The question ITSELF says that the character ONLY appears once, and where it appears is in a stage direction.
It HAS to be the bear.
Do any of these babies or corpses or ghosts you are thinking of appear only in a stage direction???
Getting into a nitpicky argument about whether a bear is a character or not is silly. There’s nothing else it could be. What other character existed only in a stage direction in a Shakespeare play?
Yes. There are multiple characters that appear only in stage directions, although relatively few of them fit the criteria of appearing only once AND being essential to the plot. (Banquo’s ghost, for example, would be a fine answer, except he shows up more than once.)
However, I think that I’ve just figured out the absolute best answer – Alarbus in Titus Andronicus. He shows up in Act 1, Scene 1 as a prisoner, never speaks, and is promptly sacrificed to the gods, touching off a whole succession of revenge plots and counter-plots. (I withdraw my earlier suggestion of Princess Elizabeth, since she’s born in Act 5 and the vast majority of events in Henry VIII could happen if she had never been born; she’s important thematically, but not so much essential to the plot.)
Alarbus is a good one, but he’s mentioned in those stage directions twice, with a lot of talking in between, so he’s definitely on stage longer than the bear. The bear is also pretty notorious.
My problem with Banquo’s ghost is that Banquo apears earlier and has lines and it would follow that the ghost and Banquo are for all practical purposes the same character.