The robust ancient trees propped up a lush green "canopy," with pale sunlight filtering through the dense leaves, leaving mottled shadows on the soil of the Forbidden Forest as a result of the Tyndall effect.
"Woof woof woof—"
"Squeak!"
Hagrid's hunting dog, Fang, darted swiftly through the thick roots of the Forbidden Forest, its long tongue dangling behind its ears, with a Niffler sitting steadily on its head—
Kabuda was struggling to stuff a shiny silver tag into its belly, which seemed to be a dog tag Hagrid made for Fang.
"Uh, hey, William, you better stay close to me... It's dangerous here. They won't attack because they recognize me, so don't stray too far," Hagrid shouted loudly as he watched the boy walking toward the lake—holding an absurdly large crossbow in his hand, though only by human standards.
"They, meaning?"
William bent down and stuffed a few bright yellow leeches into his pocket—even though they were not scarce in the Room of Requirement now, "scraping" had become a habit for him, fortunately, he generally carried pockets with the Traceless Extension charm applied.
"Uh, well, the creatures in the Forbidden Forest. You know, I have a good relationship with the Centaur Tribe, wolves... uh, and them."
Hagrid realized his slip of the tongue, coughed twice, and tried to divert the topic, "Logically, this area should be their territory, how come recently..."
"The Werewolf Clan? Isn't that a rumor?" William chuckled, "Don't hide it, Hagrid. I've followed you here, who can possibly live so deep in the Forbidden Forest? Or perhaps, what we're looking for isn't human?"
Even though he pulled Dumbledore's name while in the castle, Hagrid stubbornly insisted he knew nothing about the monsters in the Secret Chamber, until William pressed him repeatedly, Hagrid reluctantly admitted he knew someone who might know.
Beyond that, he wasn't planning to reveal more, instead leading William all the way into the Forbidden Forest.
Initially, Hagrid planned to have William wait at the hut while he went to ask this "person," but clearly, William wasn't agreeable—
"If he were willing to tell you, you wouldn't have been kept in the dark for the last fifty years."
"But..."
"Besides, Dumbledore wants to know—"
Indeed, Dumbledore was a trump card for "negotiating" with Rubeus Hagrid. Regardless of how resistant the other party was, if you mentioned the old headmaster, he would likely, after some hesitation, choose to comply—
Even though he hadn't actually confirmed with Dumbledore.
"I..."
"Woof... woof!"
Before Hagrid could retort, an urgent barking interrupted their conversation.
"Fang—"
Upon hearing the sound, Hagrid instinctively turned around, striding toward the source of the sound but not forgetting to call back to William, "Quick, stay by me, don't fall too far behind—"
The giant took large strides, with William's stride being about a third of Hagrid's. Yet he quickly caught up with the latter.
The two of them found Fang barking wildly, the big black dog was clawing at a sturdy trunk, barking fiercely at the canopy above—while the Niffler sat on its head, clutching a pair of small golden bells it had "borrowed" (stolen) from somewhere, shaking them energetically.
"Strange..."
Hagrid looked puzzled at the canopy, then lowered his gaze to his hound. As its owner, he knew Fang's temperament well, even when with him, Fang rarely behaved so... brashly in a place like the Forbidden Forest.
"What's above?"
William tilted his head back, and the dark green canopy looked impenetrable.
"I don't kn—"
"Woof woof!"
Just as Hagrid was about to shake his head, Fang, which had only just quieted down upon seeing the two arrive, barked twice more. Kabuda, sitting on its head, also stood up, its two pink paws gesturing emphatically—
"A spider?" William nodded, noticing the fresh marks on the trunk, indicating the spider was quite large.
Hearing the word, Hagrid seemed hesitant to speak. He remained silent for a moment, was just about to say something, but upon looking down at William, his expression suddenly turned to sheer panic as he instinctively raised the Giant Crossbow in his hand—
"Whoosh—"
With an arrow slicing through the air, a colossal spider nearly the size of a horse was pinned to the ground.
"Oh."
William, at that moment, belatedly turned his head, the light in his eyes dimming—
He quickly walked forward, observing the hideous creature that, after a brief struggle, was now utterly lifeless, then pulled a bottle from his pocket.
A pint (1 imperial pint = 568.26 ml) of Acromantula venom could be worth about 100 Galleons.
Though he didn't lack the stuff, wastage was a shame.
"... This is what I was telling you about dan—uh, what are you doing?"
Hagrid shook his head, sighing, but was noticeably taken aback upon seeing William's actions.
"Nothing, go on—"
William shook his head and pocketed the bottle in satisfaction.
"Alright, alright then," Hagrid found William's behavior on the way here odd, as if they weren't in the dangerous Forbidden Forest but casually strolling in the garden, "But, they recognize me, they shouldn't attack outright, not sure what's going on with them lately..."
"Uh, I might know..." William rubbed his nose, "So, who exactly are we looking for in this backwater place?" Acromantula may have a taste for human flesh, but it's not like there are many people wandering in the Forbidden Forest, and birds are part of their diet.
"... Fine, I'm not sure how much Dumbledore told you, but, but Aragog really can't be the culprit, it was only the size of a Chihuahua at the time, I kept it in the castle basement, how could it have attacked anyone?" Hagrid earnestly said.
"Wait, Aragog? What on earth is that?"
"Uh, a very, very, very friendly little spider," Hagrid stressed thrice, "Besides, it knows what the monster in the castle is, even though it's always unwilling to tell me—"
"... But, isn't it illegal to keep Acromantulas?" William's gaze was puzzled—not to mention, mate, you're raising man-eating spiders in the castle? No wonder Dumbledore tolerated me keeping a few chickens in the corridor, this isn't so unreasonable, is it?
"But it's really very, very, very friendly!"
"..."
William paused for a moment, no longer focusing on a debate over a spider's friendliness, "Alright, if we're here to find it, lead the way."
"Okay then, just make sure you stay by my side, they won't attack me," Hagrid said, though his confidence wavered as he looked at the pinned, lifeless vicious spider, "… they shouldn't, anyway." he added.