When they arrived at the Defense Against the Dark Arts Class classroom, even though Quirrell hadn't entered yet, a strong smell of garlic still permeated the room.

Had the entire classroom been marinated?

Chen Yu quickly cast a Bubblehead Charm on himself.

A bubble immediately appeared around his head, looking like a goldfish bowl inverted over his head.

Ron saw the 'goldfish bowl' inverted over Chen Yu's head and pointed at him, laughing, which made the surrounding Little Wizards laugh too.

"Hahaha! Chen Yu, what are you doing? Why did you suddenly put a goldfish bowl on your head? It looks so funny!"

Chen Yu scanned the laughing Little Wizards around him and smiled warmly: "This is a Bubblehead Charm, a spell I found in 'Defensive Charms for Self-Defense'. Its purpose is for underwater breathing or to isolate foul air. Ron, since you find wearing a Bubblehead Charm a bit funny, it looks like you don't need it, right?"

After speaking, he looked at Ron playfully.

"Isolate polluted air? Can it isolate the garlic smell in this classroom? If so, Chen Yu, get me one too!"

Harry's eyes lit up. He also hated the garlic-filled classroom and, if possible, didn't want to stay in it smelling the pungent garlic.

"Of course, Harry!"

Chen Yu waved his wand and pointed it at Harry's forehead.

Instantly, a goldfish-like bubble enveloped Harry's head.

Harry excitedly said, "What a magical spell! I really can't smell the garlic!"

Hearing Harry's words, Ron looked at Chen Yu, then at Harry, his heart caught in a dilemma.

Which was more important: 'dignity' or 'comfort'?

Finally, remembering the scene where his eyes were stung shut when Professor Quirrell came close, he slumped his shoulders and said to Chen Yu, "Please, give me a Bubblehead Charm too!"

A smile slowly appeared on Chen Yu's face, and he asked in a questioning tone, "Don't you think putting a goldfish bowl on your head looks funny?"

Ron quickly shook his head and said, "No! No! No! How could I! Your helmet looks really cool! It's like... it's like... it's like..."

Ron was at a loss for words, talking for a long time without being able to say what it was like.

Fortunately, Hermione walked over, surveyed Chen Yu's appearance, and said, "It's like an astronaut!"

Ron didn't know what an astronaut meant but understood that Hermione was probably saying something good, so he quickly followed up.

"Yes, yes, yes! Like an astronaut!"

"Alright, I'll give you one!"

Chen Yu gave Ron a Bubblehead Charm, then turned and pointed his wand at Hermione, asking, "Do you want one too?"

Hermione raised her eyebrows, leaned back, crossed her arms, and made an 'X' shape with her hands, saying, "No, I'll do it myself."

After speaking, she cast a Bubblehead Charm on herself with her own spell.

Only after Hermione finished casting the spell did she realize: "By the way, if we attend Professor Quirrell's class like this, will Professor Quirrell get angry? Aren't we being a bit too disrespectful to the professor?"

Hearing Hermione's words, Ron scoffed: "Professor Quirrell's smell is enough to suffocate someone! This isn't a question of respect or disrespect; it's a question of whether you still want your nose! Last time after Defense Against the Dark Arts Class, I was completely dazed, everything smelled of garlic, my eyes were so stung I couldn't open them, tears streamed down, and I almost fell down an empty staircase when leaving the classroom! Isn't that right, Harry?"

Harry was looking at his 'Dark Forces: A Guide to Self-Protection' textbook when he heard Ron call him. He looked at Ron blankly, with a clear foolishness in his eyes, and subconsciously said, "Yes, yes, yes."

This Defense Against the Dark Arts Class class was attended by both Gryffindor and Ravenclaw.

The Little Wizards of Ravenclaw were quick learners, and many had already learned the Bubblehead Charm.

Seeing Chen Yu, Harry, Ron, and Hermione all using the Bubblehead Charm to block out the classroom's smell, they also began to imitate them in earnest.

Not many Gryffindor Little Wizards knew the Bubblehead Charm, but they also wanted to use it to block out the garlic smell in the classroom, so they flocked to Chen Yu and the others, hoping to get a Bubblehead Charm buff.

Chen Yu grandly waved his hand, indicating that he, Chen Yu, would handle all the Bubblehead Charms for this class.

He told the Little Wizards who didn't know the Bubblehead Charm to line up, one by one, to stick their heads out so he could cast the buff on them.

This also served to practice his proficiency with the Bubblehead Charm.

When Professor Quirrell walked into the classroom, he paused, taken aback.

Almost all the Little Wizards had air bubbles on their heads, sitting quietly in their seats, looking like an astronaut meeting, which was exceptionally comical.

Quirrell also cast a Bubblehead Charm on himself, joining the 'astronaut' collective, and walked unsteadily towards the podium, stumbling and speaking as he went: "I... I, I know many of you dislike the garlic smell... scent on me, so I won't force you to remove your Bubblehead Charms. Th... this class, we will talk... talk about when to use the Bubblehead Charm, as... as well as its precautions."

For Professor Quirrell, the reason he used the garlic smell to cover up his own peculiar scent was to prevent people from discovering Lord Voldemort on the back of his head.

As long as these Little Wizards didn't notice anything unusual about him, whether they used the Bubblehead Charm or not was not within his scope of concern.

With the Bubblehead Charm, Chen Yu could finally concentrate on listening.

Professor Quirrell still had some tricks up his sleeve; while explaining the Bubblehead Charm, he also demonstrated how to shrink it, making it only cover the mouth, nose, and eyes. This reduced both magic consumption and the charm's resistance in water, making it easier to swim underwater.

After all, magic sometimes had a bit of science to it. If the Bubblehead Charm enveloped the entire head, the air density would be less than water density, making it difficult to sink, requiring more effort to dive to the bottom.

Shrinking the Bubblehead Charm to just cover the mouth, nose, and eyes greatly reduced the air inside the charm, making swimming underwater much less effort.

After Defense Against the Dark Arts Class class, the group of Little Wizards went to the Great Hall again to finish their homework.

Chen Yu once again asked the Hogwarts House-elves for lunch in advance and wolfed it down.

Such a scene was already somewhat commonplace for the Gryffindor Little Wizards.

Hogwarts House-elves usually remained invisible during the day. In their words, only by completing chores without the master noticing their presence could they be good House-elves.

During the day, Hogwarts House-elves generally worked while invisible.

This also made many Little Wizards curious when they first arrived at Hogwarts and saw mops or rags that seemed to work by themselves.

In reality, these moving mops or rags were being operated by invisible House-elves behind them.

However, invisibility consumed magic, so House-elves usually weren't invisible when cleaning late at night or very early in the morning.

If Chen Yu hadn't arrived at the dining hall earlier, he wouldn't have stumbled upon Dora and the other pixies cleaning.

It was precisely because of this that he was able to build a good relationship with the Hogwarts pixies.

Now they had a secret signal: as long as Chen Yu snapped his fingers twice in the Great Hall, an invisible House-elf would hear the sound and apparate meat from the kitchen to the dining hall.