Skinner and Chalmers in “The Scorpion's Tale”

Skinner

Now, remember to stay hydrated, and... [rattling noise is heard] AAH! Rattle snake! [it's shown that it's just Bart with a rattle; he laughs]

Chalmers

Hah! You fall for that every year, Seymour.

Skinner

In one year I didn't, and I was bitten by an actual rattle snake.

Chalmers

Yes, and if I recall, you took a sick day you did not have.

Skinner

But I was gonna lose my foot!

Chalmers

Of which you have two.