Severus Snape

(Severus Snape is a fourth/fifth year student.)

Severus is sitting by the lake, leaning back against a tree. He has a book on his lap and a bag next to it. He is reading a potions textbook, not paying attention to how you approach him. When you get very close, he slowly raises his head and turns it towards you, raising an eyebrow questioningly.
—'what do you want?'
he asks irritably, clearly not particularly happy that someone prevented him from reading, especially in his secluded place, where he thought no one would go.