We had those too! We referred to them as Good and Bad. I have video of Vegas as a little guy and newly introduced to Good. He was very cautious!
Vegas had his green everlasting fun ball and O has her stinky bear and/or stinky puppy.
Here is Vegas as a puppy. He already loved the ball on the left and the right of the Good Cuz ball. I even put pnut butter on the top of Good....but he was still very leery of it. Was it because it was new? Green? Or because it had feet?
(Vegas still has his tail in this video!!)