This episode features the first appearance of Professor Miles Warren outside of the comics. In the comics, Warren is mostly known as the costumed villain, The Jackal.
Just as like the previous episode, The Return of Hydro-Man: Part 1 (1997), Peter Parker wears the brown jack and green shirt like the Peter Parker action figure from the toyline based on the show.
Professor Miles Warren is operating out of Green Goblin's underwater lab. It was destroyed at the end of Sins of the Fathers Chapter 4: Enter the Green Goblin (1996), but was brought back for Professor Warrren. Warren's cloning experiments were banned by the government and he used the lab to continue his research in secret on an underground level.
Warren decided to use DNA from Hydro-Man, found at the scene of his demise, to make clones after reading an article in the Daily Bugle that mentioned how Hydro-Man was able to dis-assemble and re-assemble himself.
When Peter and Mary Jane are walking on the George Washington Bridge to trace back Mary Jane's memories, they both agree that they hate this bridge with Peter mentioning always feeling like something bad is going to happen on it. Soon after they are attacked by Hydro-Man.