Sweet Adeline - The song sung by some of the Timmy clones is an actual barbershop quartet song from 1903.
Timmy clones giving Vicky a headache and scaring her.
This is the first episode to feature a character having clones of themselves. The second will be in "Escape from Unwish Island!", where Timmy's clones return (See Reference Fact #1) and the third in "Tons of Timmys."
Timmy's clones appear again on Unwish Island, where Timmy uses them to please the restless creatures/people that he wished away. The inhabitants of Unwish Island use the Timmy clones as servants, volleyballs and drums at their beach club.
When the clones were arguing, Timmy was floating without wings.
When Timmy put a bunch of mirrors behind him, he was facing away from them. Therefore, his back should have been shown in the mirror, not his front.
When Timmy says, "Uh oh," his mouth does not move.
In the final scene, Timmy finds Vicky in Mrs. Turner's closet. However, the two leave Mrs. Turner's bathroom.
Timmy: Hey Mom! Dad! You guys ready to have some fun?
Mr. Turner: We sure are, son. Remember, today's the day of the big... Plunger Festival!
Timmy: Mom, Dad, if it's all the same to you, I'd rather stay here and retain my dignity.
Mr. Turner: Hmm, dignity. I have no idea what that means.
Timmy: Anything else?
Vicky: Yes - I crave amusement! [sticks a jester hat on his head]
Timmy: [hops about] Yuk-yuk-yuk-yuk-yuk. Okay, I've had it!
Vicky: Oh, poor little runt. I hope I'm not overworking him. Oh wait - yes I do! [cackles]
Timmy: All right, men, your mission is to clean up this house and take care of the dragon-lady. Any questions? [he notices the half-sized clone, who strikes a pose] CHARGE!
Timmy clones: [marching out the door] Hut, hut, hut, hut, hut, hut, hut!