I traded the Yoshi doll with the mother in the house with two doors. She gave me a red ribbon in return and it said I should trade this with someone else. Who do you trade it with?
Once you have the ribbon go to the house with the chain chomp dog sitting outside of it. If you look to the right side of the dog, there is a smaller entrance to this house. Go inside here, the dog cant harm you. Inside will be a baby chomp. Speak to him and give him the ribbon.