Do the Pokemon you put in Pokemon Dream World, affect the Dream World in any way?
I put Shuppet in Pokemon Dream World for two days in a row and got a lot of Spooky Manor maps and played a lot of Blow Out Candles on both days.
But today I put Shuckle in and I got 90% Rugged Mountain, with at least 13 Collect Gems.
Best Answer
Yes, as awesomesocks42 mentions the type of Pokemon you put to sleep influences which area of the Dream World you will visit.
Here is a list to help you determine which type will increase your chances to visit a particular area:
Source: Smogon Dream World Research Thread