Four tall stags at the green mountain the lucky hunter sang before.
Here's where things really heat up. Before, we had a bugle and then an arrow following the deer. Now we have the honest-to-goodness hunter following the deer up the mountain. But, just as in every other stanza of this poem, we're drawn to the deer first and the hunter afterward.
Why start with the deer? Why make them the focus of the poem? Well, for starters, we could think about it like a typical action movie. Who's the hero? It's usually the person we see first in the film, which makes us think that our sympathies might just be with the deer, after all.
Still, that raises some serious questions about the speaker's love. Notice the article that begins line 30? It's not a possessive pronoun—"my" lucky hunter—like it was "my love" in line 1. No, now it's just "the" hunter. This makes us think that the speaker is putting a small bit of separation between himself and the lady out hunting.
Why? Well, if we add up all of the increasingly violent adjectives in the poem, we come up with a pretty grim equation: his lover might just be a violent killer. Yipe.