The Crocker Cave was just a phone booth here in this episode, but it's turned into a high-tech facility in the later episodes. This suggests that Crocker, at some point after this episode, somehow got a lot of money and used it to create the said high-tech facility.
If fairies don't need to use the bathroom then why does Cosmo (and later Poof) sometimes wear diapers in some episodes? Also in some of the later episodes, fairies are shown going to the bathroom occasionally because they need to use the toilet. (i.e. In "Truth or Cosmoquences", Cosmo went to the bathroom because he had to go)
At one scene when Cosmo yells "COFFEE!", he has buck teeth like Timmy.
When Crocker approaches Cosmo and Wanda, and looks at Timmy, you will see that his buck teeth are missing. But when Timmy is apologizing to Crocker, his buck teeth are back.
According to this episode, fairies can't breath, don't need to go to the bathroom, and are immune to electricity, but in the next few episodes it's shown that this is not totally true. (All of this could just be Crocker's assumption however).
The last one is the only one that Crocker actually assumed. The others were actually stated or implied by Cosmo and Wanda while they were in human form. Also, it may not be that they are necessarily immune to electricity. It just does not kill them because they are immortal and fast healers.
Mr. Crocker said that if Cosmo survived the electric chair, then it proves that he is a fairy, but he himself survived the electric chair, so he should have thought he himself is a fairy.
A.J. is extremely smart, so he should have recognized the Pollywallyoptasaurus as a real living being.
A.J. might not have believed that it could be possible, especially since Timmy (not some scientist) was the one that brought it in, despite the evidence of his own eyes. Alternatively, that may be because extremely smart does not mean "knows everything about everything, and able to identify everything as exactly what it is or simply know whether it's fake or not."
When Chester and A.J. argue over who should go into the girls' bathroom, A.J. initially keeps repeating "I'm not goin' in, you go in." But when we see them continuing the same argument some time later, A.J. now just says "No, you go in."
Cosmo and Wanda always tripping or bumping into objects while Crocker does the same thing.
Cosmo and Wanda not knowing the basics on being humans.
Characters thinking that the pollywallyoptasaurus is a chicken.
A.J. and Chester setting off a cuckoo clock at Mr. Crocker at random times.
Cosmo: It was my idea!
Wanda: No, it was my idea.
Cosmo: Well, it was my idea to take your idea!
(the Pollywollyoptsaurus spits on Timmy's face)
Cosmo: It was her idea!
Crocker: A dinosaur? Extraordinary. No normal child could have access to that type of genetic technology. There's only one logical explanation.... FAIRY GODPARENTS!
Mr. Crocker: That's alright, Mr. Turner. No harm done. I would however like to have a word with your Fairy God...I mean, parents! Plain, ordinary, everyday, don't have magical powers, parents. First thing tomorrow.
Timmy:Breathe, bird-brain, you have lungs now. You...have...to...breathe!
Wanda:You mean all the time?
Timmy:Huh, you guys follow me. we'll work on some other human stuff. (Cosmo and Wanda run into the wall) You have to use the door now. you can't just walk through walls. Your solid now.
Cosmo:you mean all the time?
Timmy: (on the phone with Chester and A.J.) Dudes, you got to help me find my show and tell thing.
A.J.: You mean the chicken?
Timmy: It wasn't a chicken. It was uh..my uncle's dog in a Pollywollyoptsaurus suit. And I gotta get it back!
Chester:We're on it!
(Chester and Timmy hang up)
A.J.: Doesn't anyone say goodbye anymore?
Mr. Crocker: It may just be a phone booth inside the janitor's closet (his fingers get trapped in the door) - OUCH! - but after I capture Timmy's fairies and harness their magical powers for my own use (his fist smashes into the top of the phone booth) - DARN IT! - I'll get not only the proper equipment, but also the respect and (his hand smacks into the door) - GAH! - admiration that I have so (his fists punch the top of the phone booth)- OWCH! - long eluded me!
Crocker:I need only to get them to sit in my special electric fairy detector chair. If they survive, they're FAIRIES! If they don't, I HAVE TENURE!! May I offer you a chair?
Cosmo: Certainly, may I offer you a fish? (Cosmo hands Crocker a fish which drops onto the ground. Crocker then steps on the fish and slips backwards, causing him to sit in his own trap and get electrocuted along with the fish which becomes fish sticks.) Oh neat fish sticks I'm starved. (Cosmo takes one of the fish sticks and starts eating it)
Crocker:Eh, I'll be right back after I chip off the dead skin.
Timmy: I think he's suspicious so be on you toes (Cosmo and Wanda tip-toed literally and fell off balance) I'm doomed.
Mr. Crocker: At last! Timmy's godpa- I mean parents, Mr. and Mrs. Godturner. It's a pleasure to meet you...
Cosmo: Yippee! That hurt!
Timmy: No, Cosmo, you're supposed to say "ouch" when something hurts
Cosmo: Oh, okay. Yippee! That ouched!
Wanda: Wow! the plan's already falling apart.
Timmy: WHERE'S THE BAT?!
Denzel Crocker: Can I offer you anything with that? Cream, sugar, magic?
Wanda: What was that last one?
Denzel Crocker: (unsure) Sugar?
Denzel crocker: Oh, perfect!
Principal Waxleplax: A week of detention for all of you! (points to Timmy) You for faking your show and tell, (points to Chester and A.J.) you two for going into the girls bathroom! (points to Crocker) And you for trapping me in a toilet paper cocoon and promising two small boys they could enslave the earth! (as Waxelplax points her finger at Crocker's nose, toilet paper on Waxelplax's finger gets stuck onto Crocker's nose) THAT'S NOT RIGHT!!!!! (Principal Waxelplax storms out of the detention room)