Scribblenauts has tens of thousands of words. Some gaming websites like to misquote that and say it only has 10,000...but no. Tens of thousands.
So you can imagine the relative difficulty one might have at coming up with some sort of comprehensive list of all the words, what they do and look like, etc. It'd be...well...time consuming. Lots of time spent in front of a DS and a dictionary.
Thankfully the guys over at Scribblenauts Guide have taken two approaches to the situation: hit it early, and hit it with the entire community.
Check it out here and feel free to add some stuff it's missing! Or, alternatively, avoid it like the plague if you want to discover these things yourself.
Of course you should also avoid most dictionaries, encyclopedias, and web forums.
Oh, and this blog.