A lot of D&D fans have noted that, unlike how Doric’s Wild Shape is presented in Dungeons & Dragons: Honor Among Thieves, D&D druids have almost never had the ability to transform into owlbears, certainly not in the latest edition of the rules. There are a number of other discrepancies, like the fact that she can switch from one form to another without stopping in her regular tiefling form, and also that she is not a spellcaster and
cannot attune the helm of disjunction.
Obviously, the movie wasn’t really following the rules anyway (the slowly-expanding time stop isn’t a thing, I don’t know what that thing on Simon’s hip was, etc.), so no critique of the movie—but it did get me thinking.
Prior to the movie, we had a question about balancing a druid turning into an owlbear and the like, but now that I’ve seen it, I’m fairly sure—despite the fact that she was called a “druid” in the movie—the druid class isn’t the best fit for Doric. One can imagine a druid circle like Circle of the Moon but that allows owlbears, perhaps instead of elementals, as suggested in the top answer to that question, but that doesn’t really capture the character that Doric is in the film.
So what I’m imagining instead is a subclass for some other class, that says you learn Druidic and count as a druid socially, and gives you a version of Wild Shape perhaps even better than Circle of the Moon’s (allowing creatures like owlbears, allowing multiple repeated shifts in quick succession, etc.)—but on a class without spellcasting. There’s precedent in D&D for that, in the master of many forms from the Complete Adventurer supplement for the “v.3.5 revised edition” of D&D (though even that, oddly enough, couldn’t turn into an owlbear).
The question is, where to put it? It has to be a class that has fairly-powerful subclasses, and that doesn’t have spellcasting. I’m leaning towards Monk, just because of the shared Wisdom focus and because the subclass could allow Martial Arts to apply to claws and the like. But I’m not super-familiar with 5e, particularly on a meta level like this where you are finding the right platform for this concept, so I’m interested in the expert opinion of this site on the subject. A good answer will not just offer a suggestion, but back it up with analysis of how these ideas fit into the base class and how they would compare with existing subclasses for that class. A sketch of what the subclass would look like seems like a good idea, though obviously this isn’t the place for fully developing (and playtesting) the subclass here.