Unfortunately, I came in towards the end of a game that Thomas and Rocky had apparently been playing for quite some time.
Rocky would run down to Thomas's feet, and he would lift Rocky back up, closer to his face.
I was only able to capture this once on video, but they'd been doing this for quite some time earlier. If you listen closely, you can hear Rocky moaning, especially towards the end of the video. He goes through periods where he constantly is making noise like this. Between Rocky and Beeps, there is rarely silence in our house.