The Calydonian Boar.

"The boar was furiously twisting its body round and round, its jaws slavering with foam and fresh blood...the hero who had dealt the wound came up close to the animal and roused his foe to fury, before finally burying his shining spear in its shoulder. -Ovid, Metamorphoses"

Midway through Black Poplar, I plan for Mina to encounter The Calydonian Boar. The boar is a legendary chthonic creature, a child of the ancient goddess Ekhis, or Echidna, the mother of all monsters. The presence of the boar itself is an opportunity to test Mina, a creature of wiles and magic, against a creature of pure physicality.

The boar was immortalized in a painting by Peter Paul Reubens in 1611 or 1612 (above). The painting currently resides at the Getty Museum. You can read more about it here.

I've tentatively titled the chapter "Bright Tusks", loosely after a description from The Iliad.

"...in wrath at his whole mighty line the Lady of Arrows sent upon them the fierce wild Boar with the shining teeth..."

The "Lady of Arrows" in question is Diana, the Roman Goddess of the hunt. Her Greek equivalent is Artemis.