That would actually work really well (if they were not straight and attracted to eachother).

Bojack often spirals negatively and pushes everyone away or brings them down. Mr PB would never give up on him, wouldn’t be dragged down emotionally when bj is sad, and might even be able to help bj be happier and form new healthy habits and do the work to process his trauma.

Bojacks too old for him but apart from that they’d be cute lol