Thanks, I appreciate the work people are putting into this. I could recommend a few more monsters if you'd like, I've run 3.5 campaigns for 5 years now and I've a few staple mosters that I find work very well, if you ever get around to them let me know, I'd love to see what you do with them.
Nightshades for example are all missing except the Nightwalker which I find the least interesting, they make great creatures for haunting a high level area or acting as subordinates to powerful liches, plus they strike me as the most creepy mindless undead.
Yrthak is a great alternative to a Dragon, I always found as Dragons are depicted as intelligent sentient creatures it was hard to justify the attacks. Yrthak though can legitimately try killing adventurers because they got too close to it's nest... this makes them a good "random battle".
Then there are some of the old Epic monsters that I don't think have been stated in 4e yet. Xixecal is one of my favourites for well... epic fights. They're so massive, it feels like something from the video game Shadow Of The Colossus. Then there's Hunefer, which are terrorfying if done right (I like using undead). And finally there's the Worm That Walks... something that I think can be not just creepy but outright disturbing and an excellent final villian for an epic campaign.
If you do make any of these, then thanks in advance and I'll let you know how they play if you'd like.