During the opening montage, there is a blink-and-you'll-miss-it shot of BoJack's television set showing a sax player and the dates 1956-2017. This is a tribute to Ralph Carney, who played with Tom Waits and co-wrote the BoJack theme song.
After Bojack asks Flip why his character Philbert's house looks like Bojack's own place, Mister Peanutbutter comments "I think it looks like David Boreanaz's house!" This is a callback to Live Fast, Diane Nguyen (2014) when Todd charges tourists (and Mister Peanutbutter) to look around Bojack's house under the guise that it is actually David Boreanaz's house.