The humble toad is a type of amphibian, with bumpy skin and venom glands. But Neville's missing toad, Trevor, isn't just any toad. He's a golden-backed toad that can turn invisible.
Golden-backed toads are a large species native to Brazil and other countries in South America. They are more handsome than most toads, but more importantly, they are known for being incredibly intelligent, earning them the nickname the "Einstein of toads." The invisibility, however, isn't a natural trait. This suggests that Neville's Trevor has the blood of some magical creature in his veins, which makes him quite a rare and expensive pet.
It's clear that Neville's family must be quite well-off. After all, you don't just happen to find an invisible toad. You can even hear the sour note in Ron's voice when he talks about a pet toad.
"If I had a toad, I'd try to lose it as fast as I could. The sooner the better."
"I didn't lose him on purpose! He always tries to run away from me!"
Neville retorted loudly. You could tell from his voice that he really loved his toad, Trevor. Perhaps because of his magical bloodline, Trevor was much smarter than a regular golden-backed toad.
"Can we help him, Dudley?" Hermione whispered, pulling gently on the sleeve of Dudley's robe. She was clearly moved by Neville's pitiful state.
Even if Hermione hadn't asked, Dudley was planning to help. It wasn't a big deal, anyway.
"I'll help you look for him."
Dudley said, putting his book away. He knew he likely wouldn't be able to get back to reading until they arrived at Hogwarts.
His first impression of Neville wasn't a great one. The lad was a crying mess and had none of the stoicism a boy his age should have. But Neville had a solid frame, and with a bit of training, he could have an impressive physique.
Neville's face lit up, but his relief was short-lived.
"If I find him, can I borrow him for a few days?"
Dudley wasn't a fan of toads, but the mucus on Trevor's body would be a fantastic ingredient for a new potion. Besides, he was curious to see how the magical toad's mucus differed from that of a regular toad.
"Y-yes, sir," Neville stammered, his face falling.
Seeing Neville agree, Dudley pulled a small vial of a cloudy, pinkish liquid from his satchel.
"Magical Creature Lure (Inferior)."
This was a byproduct from one of his failed attempts at potion-making. It was a good thing he had his unique system to tell him what it was; otherwise, he would have likely thrown it away as a failure. As the system often reminded him, knowledge is a necessary condition for a spellcaster. Even failed potions aren't always useless.
Dudley asked Neville for a bit of Trevor's food, then carefully squeezed a single drop of the pink liquid onto it. He only had one vial of the stuff and hadn't figured out how to make it consistently yet.
A faint, strange scent began to fill the compartment, though only magical creatures and Dudley could smell it.
A moment later, something amazing happened.
"Ribbit… Ribbit…"
With a few distinct hops, a golden-backed toad about the size of Dudley's palm slowly appeared on the table, greedily devouring its food.
"Oh, Trevor! You're back!"
Neville grabbed the toad happily and hugged him tight.
Dudley finally understood why Trevor was trying to escape. For a cold-blooded amphibian that loves dark, damp places, Neville's constant hugging was a form of torture. Human body temperature was simply too high for them. No wonder he tried to run away.
"Is that a potion?" Ron stared at the small vial in Dudley's hand. "I've heard Fred and George say that potions can do things that spells can't."
"Harry, did your brother brew that himself?"
When Harry gave a firm nod, Ron lowered his voice and whispered, "Your brother is amazing." He then grumbled to himself so only he could hear, "Unlike my brothers, who only know how to torment me."
It wasn't unheard of for new wizards to teach themselves a few simple spells before school, but a boy who could brew potions on his own was unheard of. Potion-making was an inherently dangerous art.
Hearing Ron praise his brother, Harry's chest swelled with pride. It made him happier than if Ron had praised him instead. He instantly felt a great fondness for the ginger-haired boy.
"That's Dudley. I've never seen anything he can't do."
Harry praised Dudley unreservedly. When it came to singing his brother's praises, Harry was a natural.
"Neville, if you really love Trevor, you should learn how to care for him properly," Dudley said, offering some advice. He then took a book out of his bag and handed it to Neville. "Take this book. It never hurts to learn a bit more."
It wasn't a book on magic, but a Muggle guide to caring for cold-blooded animals. It just so happened to have a section on amphibians.
Dudley's luggage was an endless pit. He had several sets of dumbbells with him, which only he could carry.
"Thank you, sir."
Neville carefully took the book, as if it were a priceless treasure. He was no longer afraid of Dudley. Instead, he felt a sense of kinship with him, and Dudley's image in his mind grew even taller.
Because of his timid nature, Neville never had many friends growing up, especially not a boy like Dudley, who had been so kind to him right away. A lump began to form in Neville's throat.
"You can just call me Dudley," Dudley said.
"Okay, Mr. Dudley."
---
The compartment door opened again, but it wasn't a gentle push like Ron's, or a polite knock like Neville's. It was shoved open violently.
Three boys entered. The one leading the charge was the platinum-blonde boy who Dudley had made cry in Diagon Alley. He didn't seem to notice Dudley, however. He walked straight up to Harry, his eyes shining with interest as he looked down at him.
"They're saying all over the train that Harry Potter's in this compartment. So it's you, is it?"