There are a few Marc Davis gags in the attraction, like the ridiculous opera valkyrie and the headless knight. The most notable of his concepts are the stretching portraits depicting normal scenes at the beginning, but revealing more creepy and unfortunate situations as the room lengthens.
The passed-out-drunk ghost under the ballroom table, and the one swinging from the chandelier.
From the Hong Kong Disneyland version, Mystic Manor:
One of the visual gags in the "Mediterranean Antiquities" room. It is an animated painting where a Roman family is dining outside, with Mt. Vesuvius in the background. The volcano erupts and lava covers the family...and then they raise their arms and clink their glasses together!
Even funnier is that the woman standing in the picture, who is waist deep in lava, has a confused expression on her face when that happens.
Albert's squeals of terror sound adorable, and despite it looking lethal, all his misadventures in the exhibits are funny, from him ducking back into a cannon every time a Samurai tries to decapitate him, him screaming as the tikis pin him to the wall, and The Monkey King's statue creating a vortex and trying to suck Albert out. And even funnier, during that sequence, A chubby panda gets sucked out of its painting screaming and lands in another one.
There's also Albert yelling in annoyance as his fez gets caught on a sword at the end and the Oh, Crap! expression on the sarcophagus' face as the scarab beetles move closer to him.
The three singing suits of armor (they are in display cases with the helmets above the armor) are a hilarious Shout-Out to the Singing Busts. What's funnier is that their heads are singing, while their armour and weapons are dancing.
Occasionally the song will be sung in Cantonese or Mandarin Chinese. When the knights do sing it, it sounds absolutely hilarious.
When the Hatbox Ghost's head flies into the box, his hat will turn toward the box and the head inside will look up, as if he's saying "Cool trick, huh?"
Jim trying to get his son to just squash one little spider. And Megan stepping in totally deadpan and whacks the bug herself. Hilarity continues to ensue.
Michael: (about the spider) I don't wanna whack it, Dad!
Megan: (whacks spider) There. Ya happy?
Jim: No, I'm not happy! I was trying to make a point to Michael about how important it is to whack your own spiders!
Megan: Whatever. (leaves)
When the Evers arrive at the house, they discover that it also boasts an absolutely gigantic graveyard stretching off into the distance.
Jim: Hey, honey? You know they have, uh...dead people in the backyard.
Sara: Well, some people have pools; some people have private cemeteries. It happens!
Megan: You're gonna sell a house...with this?
Jim: This historical sprawling manor with spacious grounds? Yes.
Sara: Hey, that's good. We'll put that on the listing.
Megan: And leave out all the dead people?!
In a slightly bizarre combination of funny and nightmare inducing,
Madame Leota: Dark spirits from the grave come forth. Lift us from the black. And show us, show us the way back.
Jim Evers: Dark spirits?! Hey, no dark spirits! Don't you make no dark spirits come out!
In the same scene.
Madame Leota: Tell me, whom do you seek?
Jim Evers: I seek the way out of here!
Madame Leota: Then you must look within.
Jim Evers: I don't want to look within, I want to look with out, are you deaf!?
The scene where Jim finds his kids, but they want to stay and help the ghosts while he just wants to leave.
Megan: They're ghosts, Dad.
Jim: They're not ghosts. We're just having hallucinations from that dinner that we ate. It was that chicken, it didn't taste right.
Emma: (insulted, Emma turns into mist and re-appears right in front of Jim) Hey!
Emma: It's not the chicken!
Sara goes looking for Jim after they've had a row, and sees what she assumes is the back of his head, as he's slumped on the sofa in the library. She apologises for their argument, and asks "Come to bed?" And then it turns out she was actually addressing a very flustered Mr. Gracey.
Once Jim, Megan and Michael have been brought up to speed on what's going on in the mansion:
Jim: You're telling me this guy is dead, and the only reason we were brought here is he wants to try to get jiggy with my wife?