I have purchased the Dr. Noy's Extra small bear, small rabbit, and medium lamb from Amazon. I have a smallish breed - he's a pup at around 10 lbs and should max out at around 15. His favorite of his animals is by far his medium sized lamb. He carries it with him everywhere. He has managed to put some holes in all three of his Dr. Noy's, so they definitely aren't indestructible, but they are very sturdy. He is teething currently and they are withstanding that phase for the most part. The medium has an advantage of having a designated pouch inside the toy for the squeaker that the extra small and small didn't have. It makes the toy a little bulkier in the middle and adds some extra popping protection for the squeaker. Great toy!