What's worse than gnoll slaver pirates riding dinosaurs?
Undead gnoll slaver pirates riding dinosaurs.
Scratch that. Have 'em ride undead dinosaurs. Ghoulish gnoll riding a skeletal triceratops? Yessir, I'll have some more of that please. But we can't just throw these badboys in anywhere! A terror like these is just begging for some kind of horrific story and setting to back it all up. Because really, if your starting point for the adventure is badass undead gnolls riding around on skeletal triceratops, then the boss has to be the gnoll necromancer-shaman riding on the back of a ghoul t-rex. You thought a t-rex was hungry? Think about how hungry he is when he hasn't eaten in several thousand years.
We'd need a good, wide-open, sprawling jungle temple for this one. With plenty of Indiana Jones style deathtraps just waiting to be set off.
And a pit full of snakes. Wait... Undead snakes.
I think it's about time I cracked open my DMG2 and started applying some monster templates.