277. Headcanon where the slytherins want to be exclusive. It is not the individualism of ravenclaw but rather something that they can be proud of. So they start picking up the weirdest hobbys or collecting odd stuff, just to do or have something nobody else does or has. They do have the need, though to actually share these things with some people, so it is not uncommon to find small groups of slytherins geeking about syncronized swimming or their collection of meteorite parts.
Submitted by @allslytherin