Namekians Character Facts

Nameks also commonly known as Namekians, are a race from Namek.
Approximately three-hundred years prior to the beginning of the Dragon Ball series, the earliest Namekians encountered on Earth (King Piccolo and his sons, though not counting Kami) were evil, destructive and caused chaos throughout the Earth until their eventual narrow defeat at the hands of Master Mutaito and his pupils (including Master Roshi and Master Shen).
It is clear that they were a well-known, space-faring race at some point in the not-too-distant past, as most of the Saiyans who came to Earth immediately recognized Piccolo as a Namekian.