NEGUMAK (aka Gnomopo)

First known visit to Earth happened only in 1989.

They abduct Humans and exercise control over the minds of their captives, which they use for their own benefit after the captives release. Reason: unknow.

This race was the "inspiration" for the alien race in the movie "Independence Day". (note of Petro and me: the ARB states the same thing about another race)

They are one of the oldest races.

They are one of the races that most Human governments fear when considering the future of Humans.