It's important to keep your room clean and put everything in its proper spot.
One lampshaded by Mrs. Robin is "Throwing everything under the bed with the crud is not cleaning up."
Berserk Button: Do not say the word "clean" around Crud.
Cardboard Prison: Our heroes escape Crud's prison when Piglet tries to clean the floor and makes a hole through it because "this floor isn't dirty, this dirt is the floor."
Chekhov's Gun: Christopher Robin's mother hands him a bar of soap to use next time he takes a bath. In the climax, Christopher uses it to defeat Crud.
Eldritch Location: Throwing all the stuff under the bed causes the gap under the bed to become a portal to a world full of giant stuff not put away. And it ain't fun.
Gonk: Both Crud and Smudge, and, to a lesser extent, the crayon soldiers.
Killed Off for Real: Both Crud and Smudge get sucked into Christopher Robin's vacuum, making them the only characters in the entire Winnie the Pooh franchise to die (or at least be disposed of permanently).
Knight of Cerebus: Although Crud is a pretty comedic villain by normal standards, he makes for a truly terrifying villain in the Winnie the Pooh universe, especially with the way Jim Cummings voices him and how the things he's doing, despite the surreal absurdity of it all, is not Played for Laughs within the story.
Muck Monster: Crud is made of the filth from under Christopher Robin's bed.
Maybe Magic, Maybe Mundane: It's never made clear whether the events of Christopher Robin and his stuffed animal friends being sucked under the bed by Crud actually happened or is only in the imagination of Christopher Robin. Although for that matter it's never made clear whether or not Christopher Robins stuffed animal friends are actually alive or not either.
May It Never Happen Again: Christopher Robin and his friends had clean his room by stuffing everything under the bed which created another dimension ruled by the evil Crud. After the gang had successfully defeated the monster, they cleaned Christopher Robin's room. His mom puts a dirty sock under his bed but he puts it in the clothes hamper so Crud will never come back.
Pooh: WE'RE COMING CHRISTOPHER ROBIIIIINNNN!!! (the skate crashes into something off-screen, a wheel rolls by, Pooh, Piglet and Tigger emerge onscreen, unharmed, yet unhappy) Pooh: But not by skate.
No Ontological Inertia: When Christopher Robin learns to clean up and defeat Crud and Sludge, it causes everyone to be sent back to the real world and the bed to return to normal.
Poke the Poodle: While Crud is pretty creepy for Pooh standards, and is willing to imprison others to achieve his plans, his ultimate intentions are the rather petty goal of making the whole world dirty.
Reverse Polarity: Crud's weapon was an "un-vacuum", a vacuum that worked in reverse, so that it would spew dirt and grim rather than suck it up. Thanks to Christopher Robin's yo-yo repairing it, Tigger was able to use it to suck up Crud and Smudge.
Scare 'Em Straight: This episode is not at all subtle with its message about the importance of cleaning up.
Shout-Out: Pooh, Christopher Robin, Piglet and Tigger might as well could have been escaping from the twister from The Wonderful Wizard of Oz in the opening.
Space Whale Aesop: Clean your room, or else an Eldritch Abomination will form from the mess, take your friends hostage, and will make the entire world dirty.
Totem Pole Trench: Pooh, Tigger, and Piglet disguise themselves as a crayon guard in this way.
Trash of the Titans: By throwing the entire mess under the bed, it becomes a world that the gang gets trapped in.
Vile Villain, Laughable Lackey: Smudge is a comically enthusiastic minion, but his boss, Crud, is much more serious than he is.
Vile Villain, Saccharine Show: Crud is a literally vile villain. He imprisons Pooh, Piglet, and Tigger, and then tries to force Christopher Robin to help him make the rest of the world dirty by saying "If you don't, YOU'LL NEVER SEE YOUR FRIENDS AGAIN!". Granted, by normal standards this hammy cartoon blob is not much worse or creepier than most Disney Afternoon villains, but he's much more so then you'd expect from one of Disney's lightest and softest universes.
Wham Episode: The first Pooh episode (or Pooh instalment of anything) to have an actual villain. Certain episodes after toy with more antagonists, even if they're usually Lighter and Softer than Crud.
