Hi! OH MAN, THE STAG. I really, really love the stag. Like, wow, I didn’t even know how much I’d love this damn stag.
I think it’s brilliant both as a reocurring show motif and dream symbol; I love how it’s so ethereally frightening and ever-present; I love how it’s an amalgam of the ravens picking at the girl’s eviscerated body and the stolen stag head; I love how it reinforces and inverts the hunter vs. the hunted trope — is it Will who’s hunting the stag, or the stag who’s hunting Will?
Arguably both, since the stag is pretty much a manifestation of Will’s uneasy subconscious re: the copycat killer and his killing method (Hannibal). But it also encompasses Hobbs, I think — Hobbs and Hannibal combined into one allegorical beast that haunts his dreams and waking nightmares. I mean, the two are definitely intertwined in reality as well; Hannibal’s first ‘gift’ to Will allows him to catch Hobbs, who kills and cannibalizes people, a trait that both he and Hannibal share (even if their iterations differ). But I do think the stag leans more towards Hannibal in terms of the ‘haunting/hunting’ metaphor; Hobbs is dead, even if his ‘legacy’ is being perpetuated, so now it’s pretty much all Hannibal and his sneaky machinations.
I also don’t think it’s just a manifestation of Will’s inner hunter and his intended prey (or his inner prey and intended hunter), it’s Will’s subconscious warning him about Hannibal. Because I think at this point Will already knows, somewhere deep, deep inside, that the copycat killer is Hannibal. The information is all there, all available to him; he just needs to put the puzzle pieces together. He could immediately make a leap, if he weren’t so entwined himself; his ties to Hannibal, his need for that kind of support and understanding, are preventing him from making a conscious connection. So to counterbalance that, his subconscious is practically screaming the clues at him. CANNIBAL RAVENSTAG, WILL. CANNIBAL RAVENSTAG.
I know that’s kind of big leap to make on my part, but! Here’s why I think it:

Hannibal, why do you own a stag statue. In your office. Right behind your therapizer chair.
I’m just saying, Will could’ve spotted that thing out of the corner of his eye — hell, he could spot it every time he sits down to talk with Hannibal, since the thing is located right over Hannibal’s shoulder as he speaks to patients — and not consciously realized. It’s all very subliminal, and I appreciate that.
Some part of me is wondering if that’s what eventually clues Will into Hannibal being the Chesapeake Ripper, instead of the diagram of Wound Man — but it’s only episode three, and speaking as someone who’s gone over Red Dragon with a fine-toothed comb, I honestly have no clue where we’re going with this prequel. Which is super exciting.
And those are my thoughts on the stag.
This basically takes everything I’ve been thinking about the fluffybutt demon dream stag and turns it into a lovely coherent intelligent bit of meta. I LOVE THE FLUFFYBUTT DREAM STAG. UGH WILL’S SUBCONSCIOUS TRYING TO WARN HIM BUT HE CAN’T SEE IT YET. UGH MY HEART.