- Numbuh 4 as Percy
- Numbuh 1 as Thomas
- Joe Balooka as Henry
- Fanboy and Chum Chum (from Fanboy & Chum Chum) as Bill and Ben
- Stan Smith (from American Dad) as Sir Topham Hatt
- Ringo Starr as UK Narrator
- George Carlin as US Narrator
- Fanboy: Oh, Numbuh 4, You are brave?
- Numbuh 4: Water's nothing to a kid with sickness.
- Chum Chum: Tell us more Numbuh 4?
- Joe Balooka: What are you kids doing here? This school is for students. Go away! Silly things!
- Numbuh 4: They're not silly!
- Joe Balooka: They are silly, and so are you, 'Water's nothing to a kid with sickness!', hah!
- Numbuh 4: Anyway, I'm not afraid of water. I like it!
- Numbuh 4: Once a kid who was insane, was afraid of a few drops of rain.
- Joe Balooka: No one ever lets me forget the time I wouldn't come out of the classroom in case the rain spoiled my coat.
- Numbuh 1: 'DANGER' means falling down something. I went past 'DANGER' once, and fell down on the mine.
- Numbuh 4: I can't see a mine.
- Narrator: He didn't know the foundations to the Quay had sunk, and that the footpaths now sloped downward to the sea.
- Numbuh 4: Stupid Board!