Wikipedia:WikiEagle

A WikiEagle is a user, [sic] capable of finding the minutest error hidden in the page. Such errors include the comma within the previous sentence. Often, but not always, they fly into the article and make the change. Like a WikiGnome, their edits are usually not noticeable unless checking through edit history, and they usually fix each error they find in separate edits, similar to the WikiCat. However, a WikiEagle does not make their edits for the purpose of inflating their edit count, or to play for power—they make them for the sole purpose of improving the encyclopedia.

How to identify WikiEagles
Wikipedians who decide to publicize their WikiEagle-like qualities on their pages by adding a userbox to their userpage with the following code:
 * ''' { {User:WikiGuiGuy/WikiEagle}}

It produces:

WikiEagles can generally be found in the view history and recent changes sections of Wikipedia. However, one does not simply seek a WikiEagle. WikiEagles are generally hidden among the vandalism, major page edits, bot edits, and other cleanup work, therefore making them difficult to spot. However, once you spot one you realize how much work they put into trying to keep Wikipedia spotless.