One of the most popular features the main BA site is the movie review section, where I tear apart movies based on their astronomy. It's fun to do; maybe a little too fun as I do tend to get carried away.
It turns out I'm not the only one. Friend of the BABlog Larry Klaes sent along an article about movie monster biology which was a lot of fun to read. He goes through why shrinking humans won't work, why expanding animals won't work, and several other creature features.
My only complaint is that he missed an obvious problem with giant insects: they can't breathe. Insects have little holes in their sides called spiracles, and oxygen diffuses into their systems through them. It's fine for tiny arthropods, but it's not efficient. That's why larger (land) creatures have lungs; they can supercharge themselves with precious O2 that way. So insects can't get too big before they suffocate. I'll note insects were bigger back in the mesozoic, but the air had more oxygen in it then as well.
Oops! I wrote that part above, somehow missing the part of the essay dealing with insect respiration. It was pointed out to me in the comments, though.
The page does have some info about squids in it, so I've notified PZ Myers, too.