Good lord, if it's not nailed down I have probably changed it. Drow? Not in my campaign. Illithid? Never heard of the word, mindflayers all the way! Extensive polytheism? Nope. The dwarves in my campaign are strongly monotheistic and xenophobic. Skinny, hyperactive, bard worshiping gnomes? Gnomes are short, semi-stout, dwarf-related fans of illusion. There are lots of things I have changed because I find them silly, inappropriate, or tasteless. Following D&D canon has never been a constraint for me.