Cancer
Mine would have to be Why did sally fall out of the tree? Because she had no arms. Knock knock. Who's there? Not sally.
Bob
A: Mike Tyson's dog.
Mat
Cancer.
In his prostatoe.
Three sleeps 'till Christmas!
Because Rudolph intentionally grounded the team...
She thought children should be seen and not herded!
An illogical situation imagined by a child.