I'm going as a cowgirl.
5 seconds sound clip from the E.T. the Extra-Terrestrial movie soundboard.
You can hear this line at 00:17:02 in the Blu-ray version of the movie.
Quote context
[...]
- Why don't you go as a goblin?
- Shut up.
- It's not that we don't believe you, honey.
- What are you going as, Gert?
- Maybe a... A... You know how they say there are alligators in the sewers?
- All we're trying to say is, maybe you just probably imagined it.
[...]