The season 31 premiere, The Winter of Our Monetized Content (2019), said that Homer would buy a boat on November 3rd, which he did in this episode, which aired on November 3rd.
The name of the whale is "Shame-u", a reference to SeaWorld's Shamu.
Carl and Lenny have a poster of Bert and Ernie on their bedroom wall.
Couch gag: The Simpsons are thrown at a dartboard. Marge hits 7, Bart hits 13, Maggie hits 12, Lisa hits 10 and Homer hits the side of the wall next to the dartboard, knocking a lamp off the side table.
The title is a reference to "Gorillas in the Mist"