One early pitch for Jaws 2 involved dropping the great white shark for another sea monster, which might have ruined the whole franchise. The original Jaws became the first true summer blockbuster in 1975, and it's rightly regarded as a classic. During this time, sequels and franchises were relatively rare, outside of the likes of the Bond movies. Jaws was such a success that the studio realized a follow-up was practically a guaranteed hit, but the sequel would - ironically - suffer through a production almost as fraught as the original.
John D. Hancock was the first director hired for Jaws 2 - which was nearly R-rated - which saw Amity becoming something of a ghost town following the events of Jaws. Chief Brody would suffer nightmares about another great white shark coming around too - which, of course, soon happens. Hancock envisioned a darker, less colorful sequel, but after clashing with producers over his version, he was fired. Jaws 2 was then rewritten and new director Jeannot Szwarc (1984's Supergirl) took over. The sequel received lukewarm reviews but was another sizable hit for Universal.
The first Jaws made Steven Spielberg's career, but it was apparent from an early point he wouldn't return to helm the follow-up. During this time, producers fielded a few concepts, including one from legendary sci-fi author Arthur C. Clarke. According to John LeMay's book Jaws Unmade: The Lost Sequels, Prequels, Remakes, and Rip-Offs, Clarke (whose epic 2001 has yet to be topped) wanted to do away with the great white shark entirely and pitched that the sequel should focus on the giant squid, Architeuthis.
There have been conflicting reports on what exactly Clarke's Jaws 2 pitch was about. Some have claimed it involved an alien object in the Indian Ocean controlling a giant shark, while Clarke only ever mentioned his story of a giant squid attacking an oil rig. Clarke also had the proposed title of Tentacles for the movie, but Jaws 2's producers quickly rejected the concept. The great white shark had come to be associated with the series, and suddenly dropping in a giant squid would have been a strange move.
After Jaws 2, Universal produced two further sequels. Both Jaws 3D and Jaws: The Revenge - which had two different endings - were successes, but they also received poor reviews and are now considered two of the worst sequels ever produced. It's doubtful Clarke's notion of a giant squid could have been any worse than the latter two entries in the Jaws franchise, and might even have made for an effective monster movie in its own right. However, Jaws 2 ultimately made the right choice in retaining the great white shark, because as the reception to Halloween III: Season Of The Witch showed in 1982, audiences don't always welcome a franchise's main villain being dropped.