Wow, the author did kinda shit research. Either that, or they're embarrassed about playing DnD and want to pretend they don't.
While the fact that there's a race of dragons so devoted to stealing brains that they are commonly dubbed Brainstealer Dragons should be more than enough to prove their strangeness, they have other issues. For instance, instead of heads they just have four tentacles shooting out of their necks, which they use to, uhÖ steal your brain.
There actually is an explanation for this, and it's weird enough that the author could've left it in if they'd known about it and it'd hype up the weird even further. There's a race of evil brain-eating mini-Cthulhu things called Illithid(or Mindflayers), and they reproduce by laying parasites in people's brains that transform their heads. I'm pretty sure Brainstealer Dragons are just what happens when Mindflayers manage to get their hands on a draconic host.
the Abyss, which is basically D&D's hell. It's where chaotic people go when they die to be continually eat alive by maggots.
people. Chaotic Neutral people go to Limbo, and Chaotic Good people to to Elysium.
These giant dragons wander Hades, which is different from the Abyss in that it's "the battlefield for the eternal Blood War," whatever that means.
It's pretty significant to the background fluff, actually. Basically, Lawful Evil souls go to one hell and become devils and Chaotic Evil souls go to another and become demons, and they fight an eternal war in Hades, the Neutral Evil plane. The Neutral Evil dead, or Yugoloths, then hire themselves out as mercenaries to the highest bidder. I'm simplifying some of it, but that's the general gist.
But did you know dragons can also be zombies? It's true!
Yeah, but anything can be a zombie if it used to be alive. You just cast Animate Dead, and it's a zombie. It's actually pretty easy.
If your Dungeon Master has you run into a Zombie Dragon, you know your DM hates you.
Not really. The zombie template isn't really much of a power boost, if any. And in the case of something like a dragon, which wins fights by being powerful and
clever, turning into a moaning idiot is definitely a downgrade in power.