Neville's surprise, and the slightest touch of indignation, was plain on his face. The least the Slytherins could do was pretend to know his name when they weren't making fun of him, given how often they made use of it when they did.
"Neville, actually," he said quietly, placing the fertilizer bucket outside the greenhouse door and retreating back inside. He gestured to the various flora on the shelves and suspended from the ceiling. "Though if you want to be called Greengrass, I guess you came to the right place."