Throughout the entire film, the length of Dorothy's hair changes, getting longer & shorter all the time.
--Near the beginning, when Dorothy is balancing on the fence, watch Zeke on the right. He picks up a bucket of feed & starts to pour some out. Notice the amount in the bucket before the next shot. In the next shot, the feed amount has dropped from being almost 3 quarters to almost empty.
--After Zeke is scared by the pigs, he runs out. Hickory & Huck walk up & taunt him. Watch Hickory on the far right. He's patting his face with a rag, holding it in his right hand. In the next shot, Hickory's hands are down & the rag is now in his left hand.
--Aunt Em gives Dorothy a cruller. Dorothy doesn't take a bite out of it. Watch as Em is walking away, Dorothy holds up the unbitten cruller. In the next shot, the cruller has a bite out of it.
--When Dorothy is hit by the window, you can tell the glass in the windows is actually plastic wrap by the way it bubbles out.
--When Dorothy first walks out into Oz, a front shot of her shows her holding her basket & Toto. Just before the shot cuts, Dorothy grabs Toto with both her hands. Next shot, & now Dorothy's right hand is stretched out to her right.
--Dorothy stops in front of the bridge. She turns & spins to her left & ends up facing a fountain just before it cuts to the next shot. Next shot & she's facing the other way towards some bushes & flowers.
--As Glinda tells the Munchkins to come out, she's holding her wand horizontal to the ground. The next shot, as she starts to sing "Come Out", & her wand is now vertical at her side.
--The Witch meets Dorothy, & is just about to leave when she says, "Just try to stay out of my way." Notice her broom handle is pointing down when she says this. Next shot, & the handle is now pointing up behind her back.
--As the Witch takes off in the smoke, we see the trap door open & the smoke come pouring out before the Witch ever reaches her spot. You can actually see the door in the smoke.
--You can see the Witch is being lowered into the trap door because her hat & broom lower into the smoke.
Thanks to Boredincava for this blooper.
--Not really a blooper but fun to look for anyway. Just before sending Dorothy on her way down the yellow brick road, Glinda kisses Dorothy's forehead, she pulls her wand back and hits her crown. You can even hear it.
Thanks to Emily Plummer for this blooper.
--When the Scarecrow & Dorothy first meet & he says, "Oh, I'm not feeling at all well. You see it's very tedious being stuck up here all day long with a pole up your back." & his next line when it cuts back to him, his mouth is moving nowhere near to what is heard. It's funny though that Dorothy's voice matches up.
--As the Scarecrow sings the final line in "If I only had a brain", he doesn't mouth it at all.
--Right after the tree hits the Scarecrow with the apple, if you look quick, you can see on the right side of the screen that Dorothy is wearing her black shoes, not the ruby slippers.
Thanks to Emily Plummer for this blooper.
--As the trees are throwing apples at Scarecrow & Dorothy, when the Scarecrow exclaims, "Hooray, I guess that did it!", his mouth isn't moving once again.
--When the Scarecrow & Tin Man snap their fingers after the Witch throws fire at Scarecrow, look at the Tin Man, the funnel on his head is facing the wrong way. Then it cuts away & when it cuts back, the funnel is right again.
--The first time Dorothy says, "Lions & Tigers & Bears, Oh MY!", by herself, she doesn't mouth the words "Oh My!"
--At the first sight of the Emerald City, a view of our heroes from the back shows Scarecrow & Tin Man far apart from each other, with Dorothy between them. In the next shot from the front, notice now The Scarecrow & Tin Man are next to each other with Dorothy standing in front of them both.
--When they're running through the poppy field, Dorothy is right behind The Lion. Next shot & Lion & what's behind him can be seen, but Dorothy is nowhere in sight!
--When Dorothy passes out in the poppies, a closeup shot of Tin Man shows him with a tear of oil running down his cheek. Next shot however, & the oil tear is gone.
--Sometimes the wire that's holding the Lion's tail up can be seen. Most noticeably when he sings, "If I Were King of the Forest".
--The Tin Man takes a pot & breaks it with his axe, to make a crown for Lion. Tin Man reaches up & places it on his head, his hand still holding it. Next shot, & the Tin Man's hand is gone from holding it.
--Same scene, notice the shape of the crown when he places it on his head. It's points are all uneven & crappy looking. Yet when it cuts to the next shot (the same shot with the blooper #19), the crown's points are even & perfect. Then when it cuts back, the crown is uneven again.
--The Wizard's guard apppears & scares everyone, knocking the crown off Lion's head. Watch as this piece of "ceramic" bounces on the ground.
--Dorothy's telling her sob story & makes the guard cry. Look in the closeup & you can see that his eyebrows are wet. Obviously, his tears are being pumped from above.
--When they enter the Witch's forest, Scarecrow is holding a gun. It's obviously made of rubber, because it bounces & jiggles.
--Lion says, "I do believe in spooks. I do believe in spooks. I do, I do, I do, I do.." In the next shot, when he's seen saying it in the Witch's crystal ball, it's the same piec of film from the previous shot.
--When the Flying Monkeys land in the forest, the three monkeys in the front land 4 times from 4 different angles.
--The Scarcrow says to Tin Man, "They tore my legs off & threw them over there." But his legs are right there underneath him, not where he points.
--When Dorothy is first seen in The Witch's castle, she jumps toward the monkey with the basket. Watch her hands, she has them spread out. Next shot, she's holding her hands together.
--Keep your eye on the hourglass. When it's last seen here, before the other heroes are seen, remember the level of sand in it. Later on, when the three are at the door, the hourglass is seen again. The level of sand is the same as it was about 10 minutes ago.
--When Lion & Tin Man are climbing the cliff & Tin Man is holding Lion's tail, a large pad or support is clearly seen under Lion's costume.
--When the guards come from behind our heroes on the cliff, watch Lion's mouth. It doesn't move with the "Ga-ga-ga" noises he's making.
--When the three run up to the door to save Dorothy, they're wearing the guard's disguises they stole. Tin Man immediately starts to chop the door. Then when Dorothy runs out of the room, somehow all of their disguises are off.
--When the Witch is killed, the guards start to say, "Hail to Dorothy!", notice Lion is standing in front of Tin Man. Next shot, & Lion is behind Tin Man. Next shot, he's now in front of Tin Man again.
--When Toto pulls aside the curtain to show the real Wizard, the Wizard says, "Pay no attention to the man..." As he says this, he's not facing the microphone that alters his voice, yet his voice is altered nevertheless.
--When Scarecrow says, "What about the heart for Tin Man & the courage for Lion?", notice the position of our four heroes. From the left it's Tin Man, Scarecrow, Dorothy & Lion. Then after Tin Man & Lion say, "And Scarecrows brain?" , it cuts. Now their positions have changed to Tin Man, Dorothy, Lion & then Scarecrow! This is so obvious, I'm surprised I never caught it before.
--It's obvious that Tin Man unties the balloon on purpose.
--When Dorothy first appears back home, in the tight closeup, notice her right ponytail is on her chest. In the next shot, it's now on her shoulder.
--In the same scene, Dorothy sits up. When she lays back down, her ponytail goes behind her body. However, whenever the camera cuts to another shot, her hair is in front again & then back again. This happens a few times.