The human race, on the other hand... is an aggressively dangerous species.

7 seconds sound clip from the Mars Attacks! (1996) movie soundboard.

You can hear this line at 00:21:39 in the Blu-ray version of the movie.

Quote context

[...]

- From the limited information available, I've made three extrapolations.

- One, our Martian friend is a carbon-based life form. Two, he breathes nitrogen. And three, the large cerebrum here indicates... telepathic potential.

- You mean they can read our thoughts?

- Potentially, yes.

- What about their intentions? Are they a friendly people?

- Logic dictates that given their extremely high level of technical development... they're an advanced culture... therefore, peaceful and enlightened.

- The human race, on the other hand... is an aggressively dangerous species.

- Now, I suspect they have more to fear from us... than we from them.

- Doctor. Thank you, professor.

- For many years, I've been refining a translating computer. The results are not perfect... but this may answer some of your questions.

- All green of skin... 800 centuries ago.

[...]