Dragons-you only get to know something of how they look and that they are cruel.In LoTR there is no dragons.Was Sauron that poor or could he bouught a little,cute... flame-throwing dragon!Hahaha
Others are werevolves-really.Werevolves are mentioned really rare-who created them?How many were they?
ANd you have many more creaatures,but I can't remember,so move on!Next!

Robin Smallburrows - he sounds so sweet from what he says to Sam, he doesn't mean no harm, he just always wanted to be a shirriff.

Fatty Bolger lead a rebellion against the ruffians and was then nearly starved to death and all we hear is how he commented on Pippin's height. Though he did get a little more attention before the quest.

Forlong as well, Lord of Lossarnach.

The man brought in 200 tall men from the mountains (the people expected more), however, they still cheered as he entered the city.

Given enough time, Lachwen, I'm sure he would have done just that. :D

As for overlooked characters, I'm with Imladris. Nobody thinks of Legolas as an overlooked character anymore because of all the fangirl attention he's gotten, but really, I always wondered about him. He's the member of the Fellowship we get to know the least. What was he doing there, how did he get there, and where had he come from before?

Also, I think Rosie Cotton is completely overlooked. Sure, her life doesn't really seem to have the drama of an Eowyn or a Galadriel (or even an Arwen) but I still want to know about her. What was so wonderful about this hobbit-lass that captured Sam Gamgee's heart so completely? Even after all he had seen and done, he returned as in love with her as he'd been when he left - so she must have been something special. Yet we only ever get to know her peripherally, in relation to Sam. So what was her story?