Something that has always interested me a lot about Musicaljuice specifically is trying to figure out who or what exactly he is.
In the movie, the rules of the Netherworld imply that everyone who has passed away was once a human at some point in time, Beetlejuice included.
While we still don't know much about Moviejuice's past, we at least have an idea that he is a several-hundred-year-old ghost with demonic powers.
While I would consider Moviejuice to be more of a demon in terms of power, I would definitely consider Toonjuice to be more of a demon overall (as in both power and physicality).
The Neitherworld was designed in a way where while the associations of death are occasionally there, it acts more like an alternate realm of otherworldly creatures rather than a full on realm of the dead. Most likely done to make the show more appropriate for its target audience. This makes Toonjuice feel more like a creature as a result.
And then... there's Musicaljuice - a consolidation of both ideas merged in a way that gets... kind of confusing?
We at least know that in the musical, Beetlejuice has never lived in the past, thanks to The Whole "Being Dead" Thing. That would mean that Musicaljuice is a bit more adjacent to Toonjuice, in this case.
This now just begs the question - What exactly makes a demon in the musical?
From this point onward, I will be getting into more non-canon/theoretical territory-
In the earlier stages of the musical, Juno was originally going to be called "Mrs. Shoggoth". A shoggoth is a fictional monster in the Cthulhu Mythos.
If you follow the idea that Juno and Beetlejuice's last name is always intended to be Shoggoth, and that it implies that they're Loveraftian-like creatures in some way, then this adds a whole new layer of interesting...
Lovecraft's monsters were described as creatures unlike anything a human being has ever seen. Creatures beyond our comprehension. If this is the case, then what does that make the Shoggoths...? Where did they even come from?
I don't think we'll ever know for sure what exactly Beetlejuice is intended to be in the musical, unless... y'know, they decide to expand upon it via some form of post-musical media?
Like a cartoon?
Right now, the idea that Beetlejuice and Juno are these strange, unknown beings genuinely intrigues me.
From everything I have found so far, it wouldn't be far fetched to believe that Beetlejuice, the way that we know him, is only a masquerade of his true form.
A strange, unknown creature hiding under a human-like skin.
At least... that is my headcanon.
