theollady, I agree that pygmys may be a legitimate word online. I found 974 instances of it on Google, and you and I have added four more!
However, for the purposes of this game the reference source is
www.m-w.com . (By the way, I didn't start the game, I've just been keeping it going for many moons.)
So, any single word is valid for this game that does not give this result at m-w.com: "The word you've entered isn't in the dictionary." It's a convoluted rule, but it allows us to use such words as
1. runs (and other verb forms and plurals that don't have their own listing at m-w.com)
2. bedlamer (which gives this result at m-w.com: "bedlamer is one of more than 1,000,000 entries available at Merriam-WebsterUnabridged.com")
Let me know if any of that isn't clear.