It laying eggs
- Seriously, it's existed since before the Big Bang, and it's been on earth for thousands upon thousands of years, why wait until 1985?
- If It is just a physical manifestation of the deadlights, how can there be more than one of It?
- Might be that It's existence as a manifestation of the deadlights made It capable of being pregnant simply because It willed it. Or... this isn't the first litter It has birthed.
- It might just be that he never wanted to have kids before. Being beaten once scared it enough to realize maybe it should have children. It didn't want competition before.
- Or maybe that was the most terrifying thing It could do to the gang, create more of Itself...
- Considering what sort of creature It is, whatever passes for its gestation/incubation period might be several thousand years long. It could have started its egglaying as soon as possible, for all we know.
Why did It completely wipe out the first European settlement over It's lair?
Shouldn't It have left some of them alive so that It would have more people to feed on 25 years later?
- Maybe it saw in their minds or souls that more people would come eventually, so It saw no reason to stint Itself?
- Maybe It was just starving. Wasn't that the first meal It had since It arrived on Earth?
- Maybe It feed on them without considering the possibilities of these puny mortals until later.
- Maybe It found this exotic new meat so tasty that It ate them all before considering there might not be anymore of them.
- It's possible to wipe out a settlement without killing all of its residents. After all, the stories had to come from somewhere; if no one survived, no one would know.
- Why does It need Henry Bowers to kill the Losers If It has so much power?
- That was pretty explicit. It's power is based on fear and emotion. If they have strong enough will, they can overcome It's power through various mental techniques as, ultimately, they do. Henry, on the other hand, is a purely physical being and can kill regardless of his victims' state of mind.
- "Magic wouldn't work on Henry. He was too stupid."
- "I can only get 'em if they half believe, but you can get 'em no matter what."