The villainous Mr. Pettigrew has a very similar design to Jasper from "101 Dalmatians" (1961).
This is the second and final appearance of Spot the Killer Whale having first appeared in the Pilot, "Whale of a Tale".
The penguins featured in this episode have almost identical designs to the Penguin Waiters who appeared in the animated sequence in "Mary Poppins" (1964).