Okay, I'll be from a friendly planet.
3 seconds sound clip from the Robot Monster (1953) movie soundboard.
You can hear this line at 00:09:51.258 in the Blu-ray version of the movie.
Quote context
[...]
- Good. Does that mean we can play house now? You promised.
- These woods are full of spacemen. It's either them or us. Come on.
- Well, if you insist. But come here.
- Wouldn't it be nicer if we could live at peace with each other?
- Okay, I'll be from a friendly planet.
- Good. Does that mean we can play house now?
- No.
- I'm friendly, but I still have to find out what they're doing here.
- You see, our job is to chip it out carefully and take it to a museum so people can study it.
[...]