Basilisk

After all the ghosts had been mobilized and searched Hogwarts Castle several times, they finally found the chubby Grub in a hidden corner.

When Xiwen arrived, he saw his chubby body floating above an abandoned classroom on the second floor of the castle, his protruding belly close to the ceiling, making him look adorable.

His entire body was in a state of semi-transparency and semi-petrification. The expression on his face was not one of terror and fear like Mannis's; instead, it seemed to convey a sense of... excitement at the sight of a predator?

Seeing the strange expression on Grub's face, Xiwen couldn't help but twitch his lips.

"So what attacked them really was a Fantastic Beasts, right? And it was a Fantastic Beasts that looked delicious..." he commented.

"I think there's nothing wrong with it," the Fat Friar nodded in agreement.

With an experimental mindset, Xiwen silently blew a breath towards the ceiling, causing Grub's body to sink into the ceiling, with only half of his body exposed in front of Xiwen and the other ghost faces.

"It seems that Grub's petrified form is getting a little closer to becoming a physical entity. I've never seen a ghost move by the wind before," Xiwen said thoughtfully, stroking his chin.

Nearly Headless Nick, shook his wobbly head and asked, "So what does this prove?"

"This seems to prove that this Fantastic Beasts's attack belongs to a magical force capable of harming at the soul level; it's very strange and very powerful," Xiwen said thoughtfully. "Currently, the only magic of this nature that I know of is the Killing Curse, meaning it's also a kind of near-rule-based magic."

"Now that we've reached this conclusion, the area we need to search for the corresponding Fantastic Beasts will be much narrower, and it will be much easier to find them."

Thinking this, Xiwen's spirits lifted slightly from the two consecutive attacks. He then said to the two ghosts beside him, "Brother, Sir Nicholas, this little fatso Grub is yours. Take him to the Hospital Wing. I believe Professor Birley and Mrs. Dallaire will come up with a treatment."

After explaining the matter, Xiwen once again drew a golden halo around himself.

"Could it involve rules-based powers related to the soul?" Newt asked in surprise at the Hog's Head, the Order of the Order of the Phoenix's temporary stronghold.

"Yes, I feel it's similar in nature to the Killing Curse, except one causes death and the other turns people to stone," Xiwen analyzed. "But essentially, they both start working from the soul and then affect the physical body through the soul."

"But that doesn't explain the little ghost's behavior," Newt frowned, puzzled. "I've never heard of a Fantastic Beasts's petrification ability affecting the physical body from the soul!"

"You haven't even heard of it?" Xiwen frowned, changing the subject. "Or think about it another way, are there any Fantastic Beasts that look delicious enough to make Grub show that predatory look on his face before he was petrified?"

Newt shook his head slightly, took out his copy of "Fantastic Beasts and Where to Find Them" from his ever-present old-fashioned briefcase, and began to carefully search through it.

"I don't think I've ever seen any animal with that ability, and it looks delicious. Either your description is wrong, or I've never actually seen such a Fantastic Beasts," Newt said doubtfully.

Despite his doubts, his expression was one of great interest. "The second one would be best. I could even add a Fantastic Beasts Encyclopedia to this book!"

Newt's excitement grew as he thought he might discover yet another Fantastic Beasts he had never seen before.

"Wait a minute!" Just as he turned to a page in Fantastic Beasts and Where to Find Them*, Newt abruptly stopped flipping through the book and asked, "I think I found a Fantastic Beasts that looks somewhat similar to the one you mentioned!"

"Oh?" Xiwen became interested as well, leaning closer to Newt to look at the book in his hands. "This Fantastic Beasts is... Basilisk?"

The book depicts a giant, dark green venomous snake with yellow eyes and a single bright red feather on its head. The Basilisk in the picture occasionally flicks its tail or changes direction, seemingly to allow the viewer a better view of its entirety.

Next to the animated image was text describing the Basilisk creature.

The Basilisk, a level X-X-X dangerous creature, also known as the King of the Basilisks. This serpent can grow to enormous sizes and typically lives for hundreds of years. It hatches from an egg hatched by a toad. The Basilisk's methods of killing are astonishing; besides its deadly fangs, its gaze can also be fatal. Anyone caught in its gaze will die instantly. Spiders will flee at the sight of the Basilisk, as Basilisk is their mortal enemy, and the Basilisk will flee in terror at the sound of a rooster crowing, as the rooster's crow is also deadly to it. -- Newt Scamander, Fantastic Beasts and Where to Find Them*

"As far as I know, the Basilisk's glare is also a form of magic at the level of rules, but like the Killing Curse, it directly takes the wizard's life, rather than petrifying them," the renowned author explained. "As for that little ghost, it probably hadn't seen such a large snake before, so it was practically drooling?"

Xiwen paused for a moment, then nodded in agreement, saying, "That is indeed quite possible."

He recalled the scene of Mannis's attack and the circumstances of Grub's attack, and slowly opened his eyes wide.

"I remember... when Mannis was attacked, his gaze was directed towards the Black Lake below the Entrance Courtyard," Xiwen said, emphasizing each word. "If making eye Basilisk would be fatal, what if the light reflected off the lake's surface? Would that be less damaging?"

"I'm not sure about that. Maybe there are other abilities of the Basilisk that I haven't discovered yet." Newt's expression became excited again as he said, "If seeing the Basilisk through the reflection in the lake reduces the damage to a wizard from death to petrification, then what about the little ghost? Judging from his expression, it doesn't seem like he saw the Basilisk through a reflection in the mirror."

"I guess, since Grub has already died once, it's impossible for him to die a second time," Xiwen said. "So, it's very likely that as a ghost, he only has a remnant soul, and the Basilisk's death gaze isn't fully effective, so it's weakened into petrification, leaving Grub in his current state."