Principal Skinner: Well, I was wrong. The lizards are a godsend.

Lisa: But isn't that a bit short-sighted? What happens when we're overrun by lizards?

Principal Skinner: No problem. We simply unleash wave after wave of Chinese needle snakes. They'll wipe out the lizards.

Lisa: But aren't the snakes even worse?

Principal Skinner: Yes, but we're prepared for that. We've lined up a fabulous type of gorilla that thrives on snake meat.

Lisa: Then we're stuck with gorillas!

Principal Skinner: No, that's the beautiful part. When wintertime rolls around, the gorillas simply freeze to death.