Back in the day, there were a bunch of nifty horror series for kids. (I say this as if they don't exist now, but since I'm 26, I don't really hang around in the kid's lit sections of book stores, since I don't want to have a good, long chat with Chris Hansen.) Of course, R.L. Stine's Goosebumps and Fear Street series are the most famous, but there was also the softcore porn-esque writing of Christopher Pike and the Scary Stories anthologies with freaky illustrations.
A subset of this was kinda-goofy series, like the ones written by Bruce Coville. The one I remember best had the catchiest title - My Teacher Is An Alien. According to Wikipedia, it came out in 1989, when I was five. However, I first stumbled across it in third or fourth grade, at one of those Scholastic book fairs that came 'round the school every couple of months. The other books are My Teacher Fried My Brains, My Teacher Glows In The Dark and My Teacher Flunked The Planet.The plot of the four-book series was pretty simple: Super nerd Peter Thompson likes cute girl Susan Simmons, but there is a bully, Duncan Dougal, in the way. Oh, and also, their teacher Mr. Smith is actually an alien named Broxholm, who has a wife who is also an alien masquerading as a teacher, who uses a device to unlock Duncan's inner brain power. You know, your typical sort of stuff.
The series morphs from what seems to be the typical "oh my goodness, my teacher is an alien stuff!" to a bit of a morality play on humanity itself. The aliens observing Earth are worried about the destructive powers of humans, with the atomic bomb foremost among their concerns. They don't want the humans to corrupt the rest of the galaxy when they eventually get out into the rest of the galaxy.
It's an interesting thing to ponder, and as a kid, I always resonated more with books that skewed toward grey-ish morals and surprising outcomes, like My Teacher Is An Alien. Also, there was a light little romance hinted at in all the books. So, as an awkward fourth grader first discovering that girls were pretty and not always cootie-faced, I always liked books and video games that hinted at something like this.
Anyway, if you're interested in the series, it's widely available. From a casual glance on eBay and Amazon, the individual books go for $0.50 to $2. Most library networks also have all four books.
The picture of the series is from this nifty interview with the creator of the series, Bruce Coville.
