Hi, I'm Alison and I play a billion million people. Well, five. I have Barney, Luke, Lee, Mel, Yakov and Valentina. They all have usernames exactly as unimaginative as this one. You know you want to hear all about them, right? Well, luckily for you I don't care about my job, so let's go.
Barney Dunstan is a sixth year Hufflepuff and was the Keeper for their Quidditch team, so I imagine he will know Henry pretty well :-) Barney is also super friendly and sporty and he's very bouncy and enthusiastic. His best friends are Cedric and Samir (only Cedric's quietness could balance out the other two, haha) but he will talk to absolutely anybody and everybody. He has a tendency to talk in run on sentences and use non-sequitors which can make him hard to follow sometimes. Coupled with the fact he's very loud and not that bright and there are plenty of people who can't stand to be around him, although very few actively dislike him. He wants to be friends! He's team Cedric all the way, although he seems to have calmed down a bit about Harry and his fans, and is actually talking to some of the Gryffindors again.
Luke Hammonds is a 7th year Ravenclaw who will know Henry from classes. Luke is a quiet and slightly socially awkward geeky muggle-born obsessed with Star Wars (his real name isn't Luke, but he chooses to use his middle name because he thinks it's awesome). He's very smart but doesn't ever put his hand up in class because he's scared of bullies. He probably won't know Henry that well because he's so quiet, but I can see Henry being friendly anyway, and Luke will talk back, albeit hesitantly. Luke supports both Hogwarts champions.
Lee Jordan is a 6th year Gryffindor. Henry will know him as Quidditch commentator and mischief-insitgator extraordinaire. As well as Quidditch and pranks, Lee also loves girls and spiders. He has a pet tarantula, but not a girlfriend, alas. I imagine he will like Henry well enough and respects his Quidditch abilities. He generally likes Hufflepuffs, although there has been some tension recently as he is a Harry supporter.
Demelza Robins aka Mel is a 5th year Gryffindor. She does love Quidditch (but hasn't made the Gryffindor team yet) and her dad is a sports journalist so she is full of inside knowledge on the game. However, her main passion is politics and debating. She will start an argument about anything and not notice that it's not fun for the other person. She is a really nice person, though, and always sticking up for the underdog and anyone she thinks of as oppressed. She's a Marxist and a Feminist and everything else. She's also half-Indian. Oh, and she loves boys and kissing! This year she has started up a model International Confederation of Wizards (we refer to it as the Model ICW), which is like the Model UN and is basically an excuse for her to debate with people from lots of countries. Demelza also talks to everyone and is team kind-of-Harry-but-Cedric-is-nice-too-and-can-we-not-fight-about-this.
Yakov Poliakoff is a Russian Jew from Durmstrang. He is the Poliakoff that Karkaroff calls a 'disgusting boy' for having food all down his robes. He is incredibly lazy and obsessed with food. Henry will know him from classes as he's 7th year, but they probably don't have much in common! Yakov's pretty friendly too and will talk to anyone who isn't mean to him. He's basically what happens when pushy parents push too far, as he's sitting there in his self-fulfilling prophecy now. Call me lazy and stupid? Oh look what happens! He honestly doesn't care who wins the tournament and is blatantly here for the food.