My son loves Dora and Diego from the NickJr. show, and I wanted to do a Go Diego Go party for him, but they have no party supplies for Diego, so you have to be creative. 

Diego often is in a jungle/safari rescuing animals, so that is what I went with.  I used greenery bought from a craft store to make the jungle, got some animals from Orientaltrading.com and bought a toy from Ebay that had a Diego, jaguar and field journal in it and decorated the cake.  See picture;s attached.

At your local party supply store you should be able to find jungle theme plates, napkins, etc.  For the kids to take home as a favor, I found some really cool safari animal stickers at the $1.00 section in Target and they also could take home some of the animals I sued to decorate at the party.