It's such a beautiful day that Phineas and Ferb decide that today is a good day to do nothing. Candace, not knowing what to do when Phineas and Ferb aren't doing anything bustable, tries to get them to do something. Meanwhile, Dr. Doofenshmirtz has created the Ugly-Inator, a device that will render anything and anyone ugly, making Doofenshmirtz handsome by comparison. Perry tries to stop him, but Doofenshmirtz has invented another device, the Slow-Motion-Inator, slowing Perry to the point where he is unable to catch up with Doofenshmirtz.
Tropes:
- 555: The number to call to order the Man Eating, Dinosaur Themed, Totally Sick Waterslide of Doom is 555-0100.
- Aborted Arc: Phineas and Ferb wake up prepared to make a railroad in the backyard, but as soon as they see how nice a day it is, they decide to just do nothing all day.
- Artist and the Band: Jeremy and the Incidentals. Also somewhat of an inside joke since the other members of Jeremy's band are background characters.
- Batman Gambit: Candace attempts to build an amusement park ride by herself in order to get Phineas and Ferb to do it instead so she can bust them. It doesn't work and she ends up almost missing Jeremy's concert because of it.
- Borrowed Catchphrase:Delivery Guy: Aren't you a little old to be building one of these things?
Candace: Why yes, yes I am. - Disability Immunity: When Perry fires the Ugly-inator at Doofenshmirtz, it does nothing to him, because he is already ugly.Doofenshmirtz: Oh no, now I'm ugly- [notices that he's unchanged] Oh, oh I get it. Hardy-har-har.
- Early-Bird Cameo: The music heard when Monogram and Carl dance and when Agent P chases Doofenshmirtz would later be used for "Platypus Walk".
- Exactly What I Aimed At: Doofenshmirtz notices Perry (in slow-mo mode) attempting to steal the Ugly-inator, which he then takes away and runs off with, mocking Perry for being too slow to catch him. Turns out Perry is trying to get to the Slow-Motion-Inator instead to reverse its effects.
- Existential Horror: Played for Laughs. Since Phineas and Ferb decide to do nothing, Candace has no one to bust, throwing off her routine.Candace: You can't do anything unless you're trying to bust them for doing something! And if they're doing nothing then... who... is... Candace?
- Failure Is the Only Option: No matter what Candace does, the boys won't do anything on their do nothing day.
- Fantasy Sequence: When Candace sees her brothers just standing like statues, she has a thought bubble about her brothers putting up decoys in order to drive her crazy.
- Inconvenient Summons: When Perry enters his lair, Monogram and Carl are onscreen at a dance club with a couple of girls. When Monogram notices Agent P, he tells Carl to give him a close up and says, "So anyway... Stop Doofenshmirtz. Hit it, Carl!" and the dance resumes.
- It's the Best Whatever, Ever!: The title of the episode itself. Also the Title Drop at the end.
- Punished with Ugly: Inverted. Perry fires the Ugly-inator, now fueled with a beautiful photo of actor Vance Ward, to turn Doofenshmirtz's hot air balloon into a beautiful one with "I Love Goodness" written on it, much to Doof's chagrin.
- Rapid-Fire Descriptors: "The Man Eating, Dinosaur Themed, Totally Sick Waterslide of Doom!"
- Record Needle Scratch: When Perry drops in to O.W.C.A. headquarters, Major Monogram and Carl are having a dance party with two women; when they realize that Perry's in the room, we hear a record scratch and Monogram tells Carl to cut to closeup.Major Monogram: So, uh... anyway... stop Doofenshmirtz! Hit it, Carl!
- Sanity Slippage: This episode essentially crosses "Driving our sister insane" off the list in the title sequence.
- Slow-Motion Fall: Perry uses the Slow-Motion-inator to slow down his fall with Handsome Movie Actor Vance Ward.
- Special Guest: Diedrich Bader (who would later go on to voice Albert) voices handsome movie actor Vance Ward.
- Take That!: Doof’s Ugly-inator turns Jeremy and his band into a grunge band and the audience into goths.
- It also turns a recliner into a deckchair.
- That Cloud Looks Like...: In one of the lyrics of Jeremy's song in the episode's credits:The clouds look like sheep and vice versa, on a do nothing day
- Throw the Dog a Bone: The day ends for Candace with her and Stacy joining Jermey’s band on a stage, as she and Jermey sing a duet together.
- Title Drop: Done by Phineas near the end after Mom comes home.Linda: Oh, I see you're still enjoying your do nothing day.
Phineas: Yeah, Mom. It was the best lazy day ever.
