One of the things I find fascinating about the early Disney features is how much the characters are threatened by death. Snow White goes into a coma and if not for the dwarfs emotional inability to say goodbye to her would be buried alive. Pinocchio dies and has to be resurrected by the Blue Fairy. Dumbo falls from a dangerous height as he grapples with losing the magic feather. Fantasia's "Night on Bald Mountain" has the dead rising from their graves. Bambi's mother dies and Bambi has to survive hunters, dogs and a forest fire, any of which are capable of killing him.
While the Disney shorts play with death, whether it's The Skeleton Dance or The Goddess of Spring, nothing in the shorts comes close to the threats that the early feature characters regularly encounter. Considering that Disney films were always considered family films, why is death such a major part of them?
I suspect that the Depression, the looming second world war and the instability of the Disney studio in the 1930's all contributed to the feeling that life was precarious. The audiences had been through a lot in their own lives, so they had a gut understanding of how quickly someone's well-being could be threatened or destroyed. Of course, as tough as the Disney characters had it, they were saved at the end. The ultimate happy ending is to cheat death and additionally get what you've struggled for, whether it's a prince, humanity, status, or just the ability to live out your life.
What's interesting is this focus on death didn't survive the early features. Perhaps the audience was exhausted after the war or the generation that lived through it and the depression didn't want to upset their own children in the 1950's. Perhaps because the Disney studio was on firmer footing after Cinderella and Disneyland, the threat of collapse was not as strong. In any case, while death is alluded to in films like Peter Pan or Lady and the Tramp, it's not nearly as compelling as it is in the early features. By the time Woolie Reitherman took over direction, death wasn't taken seriously. Baloo's "death" in The Jungle Book is a momentary tug at the heart en route to some baggy pants comedy.
The whale chase in Pinocchio is exciting for many reasons. It's beautifully laid out and cut. The action and effects animation are done well. Monstro is imposing in terms of his size and strength. But it is the life and death nature of the chase that gives it most of its power. Geppetto and Pinocchio are overmatched against Monstro. They are literally swimming for their lives, not hoping to best Monstro in any way, just to avoid his wrath. The threat of death, convincingly portrayed by the artists, means that we fear for the characters and that emotional connection is what makes our hearts race.