in Pokemon diamond go to iron island and find a camper trainer and fight her
There is no trainer in platinum that is willing to trade a munchlax.
Sorry but there isn't a trainer with a bagon in platinum.
you can find the trainer with the misdreavus in platinum in hearthome city i believe
no one no trainer has a kingdra in Pokemon platinum exept for me :P
The trainer in victory road
You cannot 'find' a cherim in Pokemon Diamond. You must first catch a Cherubi, and then level it up to where it can evolve into a Cherim.
A trainer on iron island has hippotas
A Trainer on route 220
A trainer has it in their party on route 221.
the trainer by that place, you know ? :)
Fight everybody in the riolu event and a cherim will be there