Prismatic Jungle -
Right in the middle of the jungle is Temple of the Divine Flame, currently inhabited by Tivoli the Tyrant. It goes down deep underground.
The Prismatic Jungle isn't really a place you go for fun or sightseeing. It's all about who's the strongest -- that's who will be on top. Not those with good hearts, nor those with a lot of money, no; it's about pure power and who will eat who.
A lot of different types of Pokemon live here, but if you're small, prepare to be chased a lot as prey. Not many Pokemon will willingly trade with Pokemon from this jungle for fear of losing a limb (or worse).
The most prominent type of Pokemon to live here is anything in the Dragon-type family, or very reptilian Pokemon. The only exception to that is Charizard - those are "kill on sight" Pokemon for Tivoli. They're simply not allowed.
If you are a girl that catches Tivoli's fancy, he will make you wear a ribbon. This essentially marks you as his. It is mandatory to wear one if he dictates it so; Pokemon marked with a ribbon are not allowed to leave the jungle if he can help it and are punished severely if caught without the ribbon on.
Oh yes, and if you're shiny, expect to be killed. Tivoli only allows that his daughter is shiny.