While watching Casper, I couldn't understand why all the other ghosts (Kat's father and Kerrigan) look like ghostly, cartoonish versions of their living selves, while Casper looks just like the character in the old animated cartoons (complete with four fingers, which he lampshades), but looks nothing like himself when he was alive (his uncles would probably also count since their living selves are never shown). However, by the movie's viewpoint, it all makes sense since according to the film, ghosts slowly lose their memories of their former selves after death. That means as Casper's memories as a living boy eventually faded away, his original face and features also faded away until he looked like a generic ghost.
This doesn't quite work out, since Dr. Harvey appears to have lost all his memories (except for a general recollection of the partying) immediately after his death. It's also implied that Casper lost his own memories shortly after dying, or else he would have offered solid proof that his father wasn't crazy for thinking he was still around. Carrigan probably only kept her memories for those few minutes after she died because she was so strong-willed, and because they related to her unfinished business. (She wasn't shown thinking of anything not directly related to the treasure or the Lazarus machine.) Or it might have been her memories where jogged because immediately after becoming a ghost, she saw Dibbs and remembered her unfinished business.
Casper could have simply turned into a ghost and look like he did when he was alive for a while. With time, the lack of memories made him lose his original shape.
Keep in mind that Carrigan is the only one who died in a non-altered state of mind. Dr. Harvey was drunk when he died, and was acting uninhibited when his ghost appeared. Casper died of pneumonia, one of the symptoms of which is a high fever, which can affect your mental state especially in a time before 95% of modern medicines were discovered and the only thing you could do for a fever was pray it went away.
Except for Carrigan and Dr. Harvey, all of the ghosts in the movie shapeshift to some extent. This is probably an ability all ghosts have because they are quite simply no longer constrained by a physical body. That their perception of themselves heavily influences how they look makes a lot of sense. As Casper and his uncles have been dead for a very long time (XIX century?) they have forgotten much about themselves, and slowly their features have faded away, whereas Carrigan and Dr. Harvey still have some awareness of who they are- or more importantly, how they perceive themselves. Carrigan, who has a huge ego, appears as a gigantic ghost, complete with voluptuous breasts and bright make up, whereas Dr. Harvey looks like a cartoony version of himself. Had they remained as ghosts for a longer time they too would've slowly forgotten their previous life until they looked as undifferentiated as Casper and his uncles. Who knows what happens to ghosts that spend centuries as such; they probably degenerate into blobs of ectoplasm or mere, invisible sensations?
A smaller example. The movie takes place in Maine. Upon reaching the house, Kat mentions that it's a nice place if you're Stephen King. Stephen King grew up in Maine, and it is also where most of his stories take place.
At the beginning of the film, we learn that Whipstaff Manor has been condemned. When a property is condemned, that normally means its condition has deteriorated so badly that it's no longer fit to be used, and the only thing left to do is take a shovel to the place and bury it. However, aside from needing new fuses for the fuse-box, Whipstaff is quite liveable as-is...or would be, were it not for three ghosts who are more than a little bit territorial. The house was almost certainly condemned solely to keep people off the property, and thus, away from the Ghostly Trio.
Houses are also condemned when they are unable to receive electricity or water service. This is even more brilliant.
The fact that Whipstaff had the poem about a "treasure" on the back of the deed. It seems strange for J.T. McFadden to have put a pretend treasure map for his son on the back of the deed to his property, until you realize—the treasure in the poem doesn't refer to Casper's childish treasure, it refers to Casper himself. The name Casper literally means "treasure." He was leaving a clue that his son was still there.
Alternatively, Mr. Mc Fadden could have been leaving the note in reference to the Lazarus machine, which you know, being a machine that can resurrect the dead, WOULD indeed be a treasure.
A legend states that people who commit suicide become ghosts. It's a bit of a stretch, but the ghosts we know became so by technically killing themselves through their own actions:
Casper says he died from getting sick due to playing in the cold for far too long, against his father's wishes.
Carrigan dies from falling off a cliff because she wasn't paying attention.
Dr. Harvey dies from falling down a manhole because he also wasn't paying attention.
None of the above count as suicide, because suicide means to kill oneself on purpose.
Stinkie, Stretch and Fatso's deaths are not revealed, but it's clear they were crazy enough to do something suicidal.
One could easily imagine Stinkie dying of poisoning, hence the toxic breath, Stretch dying of hanging, and Fatso dying of a heart attack or an illness related to being morbidly obese. All three could've easily been self inflicted.
Why is Kat not sad or annoyed when Casper causes all the party guests to run out? She clearly wasn't having much of a good time considering before Casper asked her to dance, she was sitting by herself and not talking to anyone. Her classmates were ignoring her at her own party. They were clearly just using her, because a haunted Victorian mansion fits the Halloween theme much better than a modern boat house.
To be fair to the other guests, when they arrived Kat just let them in and then ran off to help Casper with the Lazarus, and the subsequent emotional upheaval of bringing her father back to life would probably stop her properly enjoying the experience.
Not only that. Kat seems ready to enjoy the party when she is sent along by her father, but then her crush, Vic, flees the house along with Amber after being spooked by the Ghostly Trio. Seeing as Vic was supposed to be her date to the party, she is now left alone. If Casper hadn't shown up, the night would've been a total loss. But by the end of it, she probably didn´t even remember Vic.
Casper's quote "Can I keep you?" has been derided by people who didn't grow up with the movie and don't like it as being really creepy. But it makes sense that Casper would say something creepy, and that it would even come into play later. It's in Casper's nature as a ghost to be frightening, and it also makes sense that he's creepy in a very innocent and accidental way. On top of that, he hasn't had a friend or contact with a normal person for decades. And above all else: Casper's only a kid. How many times have kids said something that, to them, sounded like harmless fun, but to an adult, sounded dirty or in this case, frightening?
Mnemonic devices are a theme in the film, from Casper's room to the pinky promise to Casper's eerie but innocent "Can I keep you?".
When we finally see Casper as a living boy, he's dressed like a bishounen pirate. It's a little jarring at first, but he had previously mentioned playing pirates with his father in the lab. Those paying attention could infer that it's his old costume, especially considering it was a Halloween party.
Ray Stanz failed because he was vastly outnumbered. Even regular ghosts take a couple of 'Busters to get in to the trap, and here he was all alone against three of them.
Ghostbusters: Afterlife potentially explains why this is: sometime after Ghostbusters II, Egon became paranoid that Gozer was going to return, but couldn't convince the others of this. As a result, he stole most of the equipment and Ecto-1 and fled to Sumerville without a word, and the team disbanded. Note that Ray in Casper only has a proton pack on him and no other busting equipment. It's all he has to work with at this point in time.
Fans have called BS on the idea of Casper being twelve, arguing that, since he acts much younger over the course of the movie, his stated age is meant to be a last-minute Ass Pull to change a Precocious Crush into genuine romantic feelings. Except all the ghosts in the film are shown to be immature, with Dr. Harvey noticeably losing maturity in the process of becoming a ghost. The idea that Casper’s ghosthood caused him to similarly regress is not at all unreasonable.
When Dr. Harvey becomes a ghost, he presumably leaves his mortal shell behind in the open construction trench where he died. After entering the Lazarus machine, he gets a fresh new body ...so what happened to his old one?
It sounds like he took a nasty fall, so probably his old body is completely damaged.
I think the original poster was implying that a construction crew is gonna find his old body.
There's always the possibility that the machine can somehow "match" a recently dead body to the spirit that occupied, and teleport said body into the machine itself from wherever it is found, fix it, and re-attach its spirit. Which would explain why Dr. Harvey comes out of the machine fully clothes and with his glasses on, rather than butt naked, AND thankfully get rid of the "body in the trench" issue. This COULD also explain why Casper was never brought back to life. Maybe Mr. Mc Fadden was unable to keep Casper's body intact for long enough to reattach it to its spirit, and ran out of time. The failure may have been what made him lose his mind and be taken to the asylum, leaving Casper literally floating. Of course this doesn't explain why Casper didn't leave the mansion and haunt the asylum instead (or perhaps he did, until his father died, and then he returned to the house...)
It actually is worse than that. For at least some of the film, without knowing it, Kat was an orphan. Amelia was dead before the events of the film and Dr. Harvey accidentally killed himself while drunk. Can't blame Kat for crying when Dr. Harvey as a ghost does remember her. Thank God Casper was able to bring Dr. Harvey back to life.
So that genuinely moving scene where Casper admits that his unfinished business was to keep his dad from being lonely? According to a newspaper clipping we see it turns out that the act of doing so drove the man insane. Oops.
It's actually worse than that, Casper's father was probably completely sane when he was sent to the nuthouse, because he was telling the truth, he was completely sane but probably constantly saying something along the lines of "My son is a ghost who hangs around with me and I'm building a machine to bring him to life". that would raise a few eyebrows even these days.
The shape and names of the Ghostly trio may provide horrifying clues to their deaths if you think about it (they obviously aren't using their real names), Fatso probably had a heart attack, Stretch was probably hung, and Stinky was poisoned/gassed (for all we know that might have been why Stretch was hung!).
Had Carrigan and Dibs not stolen the Lazarus serum, Kat and Casper would have been utterly screwed. True, Casper would have been brought back to life, but without the formula, Dr. Harvey, Kat's father, would have stayed dead. Eventually, Carrigan and Dibs would have discovered the two kids living alone, with Dr. Harvey a ghost. The probable result: Kat and Casper are taken away by the authorities and likely end up in foster care. Given that they aren't even family, they are probably separated as well. Worse still, in an era of Social Security numbers, birth certificates, and school records, Casper has no documentation establishing his identity, and claims the identity of a kid who died decades ago. (No one is going to believe that he's a revived ghost.) Thus, by failing to bring Casper back to life, the kids both dodged a bullet. Nice Job Fixing It, Villain indeed.
, which is a possible post-credits scene.