Krillin, Zeshin and others in “Unfinished Business”

Krillin

I wonder if the people who attacked with Frieza were Saiyans. Hey, do you remember if the people that conquered your planet had tails that came out about this far?

A tail? I didn't see a tail on any of them.

Krillin

Oh, well, so much for that brilliant theory Krillin.

That means, there's a group of warriors out there even more evil than Saiyans.