oddity
Something very strange or different from what is normal.
An oddity is something strange, unusual, or out of the ordinary. When you encounter an oddity, you notice it because it doesn't fit the normal pattern. A three-legged dog is an oddity at the dog park. A student who loves doing extra homework might be considered an oddity among their classmates. A house painted entirely in purple polka dots would be an oddity in most neighborhoods.
An oddity stands out precisely because it's different from what you typically expect. Museums sometimes display oddities from nature, like two-headed turtles or rocks that look exactly like human faces. Collections of strange and curious objects are sometimes called cabinets of curiosities.
Being an oddity isn't necessarily bad. Many successful inventors, artists, and scientists were considered oddities in their time because they thought differently from everyone else. The key is that an oddity is noticeably different. A book about marine biology wouldn't be an oddity in a library, but it might be an oddity sitting on a shelf between cookbooks and sports magazines. The word captures that moment when you stop and think, “Huh, that's strange” or “You don't see that every day.”