Defense Against Magical Creatures Lesson One (Open to Defense Against Magical Creatures Students only)

The second and third years enter the classroom less nervously than the first years did, all of them knowing me and being comfortable in the school already. When they all file in and sit down, I stand up and smile. "Welcome back everyone. It's nice to see you all. I'm very excited to introduce you all to some very interesting creatures this year," I grin. Most of the students smile, excited.
"Now, first off, a few questions. Can anyone tell me what this is?" I ask, levitating a large glass case up onto my desk. Inside is what appears to be a small rock with hair, but I know differently.
"A rock?" a student asks sarcastically.
"No. Next?"
Another student raises their hand. "A Pogrebin?" they ask.
"Yes, correct, but next time, be more confident in your answer like they were," I say pointing at the sarcastic student. "Don't ask if it's a Pogrebin, tell me it's a Pogrebin." I smile reassuringly at them. "You need to be confident in naming what these are so that you can deal with them. Still, five points.
"Now, what do Pogrebins do?" I ask. A student answers correctly and I award them five points. "Excellent. So, how do we stop this from happening? What can we do to defend against Pogrebins?"

((OOC: First to answer the questions gets the points, only one question per student, the last question, I want to see everyone answer based on their research (there is no real answer to be found online, so you need to actually think) and I will let you know what is correct.))

I sit down in the classroom. Someone answers his first question, which gives me an idea of how to answer his next question.
"What do Pogrebins do?" he asks. I raise my hand.
"They follow humans around and make them feel lousy until they collapse. Then it eats them. It pretends to be a rock."
"Excellend. So how do we stop this from happening? What can we do to defend against Pogrebins?"
I sit back and wait for an answer from someone else.

I waited for someone to answer but I decided to go ahead and say something. I raise my hand and Professor Black points to me.
"If necessary there's always a cheering charm. Once the effects of the Pogrebin set in you should be able to figure out that there's one around you. I mean, it would be strange to feel suddenly lousy unless you've had a horrible day. And if you know it's around then can't you attempt to capture it or scare it off?" I ask trying to remember spells that would be useful other than cheering charms.

I glare at the Slytherin as he answers. I hate that he gets points for his awful house. Maybe somehow I can make him lose points today, I think. I continue to glare at him, hoping he notices and gets upset so that I can make him lose points somehow.

I noticed that a Gryffindor was staring, or rather, glaring very intensely at me after I answered Professor Black's question. He looked very familiar and then I remembered the train. I shouldn't even bother with him... I thought as I turned my attention back to Professor Black. Although... I began to plot as I thought of how much fun it might be to mess with him just a little. Nah I shouldn't bother with him, he's just being very uncool about the total situation, I decided as I focused more on the lesson rather than him. But his glare made it hard, I could practically feel him pointing his wand at me and setting my hair on fire, or something resembling that.