Dopey is a man of few words, but many expressions.
The Disney film
During the digging segment at the start of "Heigh Ho", the dwarf mine makes some... unusual echoes.
Bashful: In a mine... Echo: In a mine... Sneezy: In a mine! Echo: In a mine! All together: Where a million diamonds... Echo: Shine!
The scene where Sneezy sneezes underneath the coat he and Dopey were wearing (which results in the coat briefly inflating to twice its original size and Dopey flying out from the top onto one of the beams near the ceiling), was hilarious enough in one's childhood that rewinding and rewatching 50 times in one session was highly necessary.
After Doc and Dopey store their mined jewels in the mine vault, Dopey diligently locks it up and then hangs the key neatly on its peg... right next to the door. It renders the entire procedure meaningless, but Dopey is so innocent you don't hold it against him. It's still funny, though.
There's a very darkly humorous scene after the Queen becomes the Hag. She walks down through the dungeon and comes across a skeleton reaching for a bucket of water. Her response?
Dopey with the soap; it constantly slips out of his hands until, after charging towards it, he swallows it by mistake. Despite the fact that he immediately starts to hiccup out bubbles, he doesn't realize where the soap is until about ten seconds later, and after a slight pause, he goes into a hiccuping frenzy that lasts for the rest of the washing scene.
Special mention to the final moments where his head gets shoved into his coat, and he hiccups a bubble out of his collar, which carries his hat into the air.
The reason he needs the soap is to wash Grumpy, but the dwarfs are already washing Grumpy with two bars of soap. One gets the idea that the dwarfs just have soap bars lying around and tell Dopey to get one when they want him out of the way.
This also means that Dopey's angry struggles to get the soap, his numerous failures and what he ultimately does to himself just by following Doc's instructions... was completely pointless. Dopey clumsily swallowed the soap, hiccuped bubbles nonstop to the point of wooziness, and missed out on washing Grumpy with the rest of the dwarfs, for absolutely no reason.
Sneezy yodeling with Dopey bobbing his head watching his Adam's apple.
Snow White's first entrance in the dwarf's cottage.
Snow White: Oh!! [the animals run away in fear] What a cute little chair.
When the dwarfs return from the mine, Dopey is the last one in the house and slams the door shut, making the rest panic for a second.
Other Dwarfs: Shh! Dopey:[while pointing at the door] Shh!
A behind-the-scenes example: Frank Thomas was animating Snow White lying on her bier while the dwarfs and animals mourned her, while Fred Spencer was animating the dancing sequence of "The Silly Song"; both done to music to set the mood. Cue them both yelling at each other, "Cut the sad stuff!" and "Stop dancing in there!"
This bit during "The Silly Song": Bashful steps up to sing his verse only to stop because he's embarrassed. Annoyed, Grumpy starts playing the verse over again, only to have Bashful stop and hide his face in his beard. Grumpy then angrily slams all the keys down on the organ, as if to say "Get on with it!". The rest of the dwarfs find it hilarious.
"HAVE A BITE?" says the Queen in Hag form as she jokingly offers the poisoned apple to her own raven. The bird scrambles away as if it thinks it will die simply by touching it. The Queen then chuckles and says "It's not for you!" the way a mother might scold a really young child for trying to get at food that, well, isn't for them.
In a creepy (yet still funny) way, the vultures. Either the witch dies and they get to nom her body... or Snow White dies and they get to nom her body... or the Dwarves die and they get to nom their bodies. Whatever the outcome, you can see them thinking, "This is gonna be a good night".
Snow White admonishes the chipmunks not to simply sweep the dust under a rug. So they sweep it into a mousehole instead. They have just enough time to wink at each other in a very smug way before their bubble is burst by the dust coming back in a gust. They dash under the rug and poke their heads out just in time to see the mouse emerge and give them an earful of indignant chatter. The mouse finishes by kicking the dust back into their faces.
The point where the dwarfs realize that the intruder is up in their bedroom. Doc decides that one of them should "go down and chase it up", er, "up, down". They all begin nodding, before they turn to Dopey, who looks arounduntil he realizes they mean him and tries to run away, only for Grumpy and Happy to grab him. Doc gives him the candle and assures him that they'll be right behind him (they stay on the first floor, at least until Dopey makes it into their bedroom). When Dopey finally gets inside, he's startled by Snow White yawning and stretching underneath the sheets. Dopey freaks out and runs downstairs, bumping into the other dwarfs, causing them all to fall downstairs. The other dwarfs freak out in turn and run out of the house one by one, slamming the door and causing Dopey to run into it. He desperately tries to pull it back open as the dwarfs collectively hold it shut from outside, thinking it's the intruder.
Grumpy warns everyone upon meeting Snow White that the Queen, due to all her powers, could be in the room right now. Dopey proceeds to look for the Queen under Happy's beard, prompting Happy to bop Dopey indignantly.
Even the huntsman has a funny moment. After he refuses to kill Snow White and falls on his knees begging for mercy, he starts crying... and uses the princess' very own dress as a handkerchief.
The Dwarfs deciding to sneak into their own house to find out who is in there...complete with squeaky shoes on the scrubbed floor.
When Grumpy warns the others from eating the soup because it "might be poison", the pot hisses and rattles, causing them to jump.
Grumpy: See? It's witch's brew!
When the Lux Radio Theatre presented their adaptation in December 1938, to celebrate the first anniversary, Walt was brought in to be interviewed by showhost Cecil B. DeMille. Cecil then asks Walt what he would do if he could do Snow White over again, and Walt responds with the following:
Having 7,000 giants (including one taller than the other 6,999) instead of Dwarfs.
Have the witch stalked by bombers instead of vultures.
The witch selling Snow White a poisoned fruitcart.
One of the Insubstantial Ingredients for the Queen's peddler disguise spell is "an old hag's cackle." Said ingredient is stored in liquid form in a glass container and kept warm by a burner on low flame. What's funny is when the Queen turns up the burner to boil the liquid and take some for the spell, the ingredient itself cackles as it boils, as if it finds the full flame tickling.
It's tricky to spot and certainly unintentional, but: when Snow White enters the dwarfs' house for the first time (12 seconds into this video) her forest friends creep in with her. The animators apparently forgot which animals they were drawing, because one rabbit hops behind another and comes out a squirrel.
The deleted sequence of the Dwarfs building a bed for Snow White is full of Funny Moments:
During the initial brainstorming before they settle on the bed:
Doc suggests a royal coach with six white herses, er, horses. Happy wonders where they'd get the horses, while Bashful points out that Snow White might leave them.
Grumpy suggests they give her something useful, like a mop. The other Dwarfs quickly shoot down that idea.
The final suggestion of the bed comes from Sleepy (since he is), who hadn't even been brainstorming with the others, like Grumpy. He also offers to try the bed out when they're finished.
Happy uses a deer's antlers as a tool rack.
As Sleepy is carving a decoration on top of one of the posts, the fly that annoys him throughout the film perches on it, and he tries to hit it with his hammer and chisel, quickly going into rapid-fire hammering Big Ball of Violence-style. When it's over, he hasn't hit the fly, but he's carved a full rabbit out of the post.
A baby bluebird is pulling out curly wood shavings from holes two other birds are boring in the headboard, but when he pulls too hard on one, he goes flying and winds up with it coiled around him.
When Grumpy's pencil point snaps off while tracing the shape of the board, he uses a squirrel (one of several chewing the wood to shape it) as a makeshift pencil sharpener.
A rabbit models for Bashful on a tree branch as he carves angels on the frame, using leaves as wings.
While carving a corkscrew groove around a post, Sneezy sneezes and goes flying all the way to the ground, completing the pattern in one fell swoop.
Happy has trouble threading a needle, so a hummingbird steps in to help by sticking its beak through the eye to grab the thread for him.
Dopey proves to be quite the sneaky bastard by gathering cloth swatches for Happy...off the undergarments of the other Dwarfs. The entire thing is made all the more hilarious by the bouncy piano rendition of his Leitmotif that plays as he does it.
His first victim is Bashful, and it gets witnessed by an intrigued squirrel who only sees Dopey's hand come in under Bashful's legs, grab his undershirt, snip off a piece, and withdraw. The squirrel stares through Bashful's legs in awe as Bashful himself looks behind him. Realizing the dwarf thinks he's responsible, the squirrel dons an "Oh, Crap!" Smile, and then Bashful bops him on the head.
Then Dopey moves on to Doc, cutting a piece from the back, and then another from the front when Doc looks up, wondering what happened. Doc ponders for a while, but shrugs it off, and when he turns away, Dopey goes full Impossible Thief by stripping Doc of his entire undershirt. Doc panics mildly, but is still none the wiser about who the culprit is.
Finally, when Dopey brings Doc's undershirt back to Happy, he starts laughing, distracting him long enough for Dopey to cut a swatch off Happy himself without him immediately realizing it. When he does, he gives Dopey a pretty good Death Glare.
At the end, Sneezy is making the mattress by churning (like butter) a bunch of soft stuff like dandelion seeds, bird feathers, and rabbit tail bits inside a large cloth. Dopey brings in some dandelions and Sneezy accidentally smells them. He tries to stave off a sneeze, but eventually grabs the corners of the cloth, shuts himself inside, and lets fly, finishing the job.
Dopey putting crystals over his eyes, as seen in the image above.