DS is 3 and a half and he has 2 friends. One is called Eddie and 'Eddie' hangs around the house and plays outside with him. He also comes shopping with us a lot. I actually had 2 guys follow us around the supermarket once listening to DS and 'Eddie' chat and me have to answer 'Eddie's' questions, absolutely killing themselves laughing.
He also has 'Pussy Cat' who comes in the car with us. We have to put Pussy's seatbelt on and make sure he is comfy, although that is usually the last we hear of PussyCat until we get home, and have to go through the production of getting Pussy Cat out of the car.
Eddie has been quite a long term thing too here so we are used to it, although it tends to freak out visitors if he mentions him ;)