Nordics are typically described as six to seven feet tall (about two metres) with long blond hair and blue eyes, and are commonly reported as being male. Their skin is said to range from fair colored to tanned, they are reported to be in excellent physical shape, and they are sometimes described as wearing skintight clothing. During the 1950s, many contactees, especially those in Europe, reported beings fitting this description. Such claims became relatively less common in subsequent decades, as the grey alien supplanted the Nordic in most accounts of extraterrestrial encounters, but Nordic aliens are still occasionally reported. Some sources, such as UFO Contact Center International, refer to Nordic-type aliens as Pleiadians, referring to the Pleiades star cluster.
Nordic aliens have been described as benevolent or even "magical" beings who want to observe and communicate with humans. Contactees have said that the Nordics are concerned about the Earth's environment or prospects for world peace, and may transmit messages telepathically. American social worker John Carpenter said that the typical Nordic, as described by those he interviewed, "is paternal, watchful, smiling, affectionate, youthful, [and] all-knowing." Stephanie Kelley-Romano says that the Nordics "are often associated with spiritual growth and love and act as protectors for the experiencers." A few claimants say that the Nordics have warned them about the grey aliens, but other claimants say that they have seen Nordics inside the same craft as greys. In such reports, the Nordics are often interpreted as leaders, with the greys as their subordinates.Jenny Randles writes that although she believes Nordics have "certainly" been involved in abductions she feels the abduction is "less essential to the encounter than it is with the [greys]."
The term "Nordic" did not come into wide use until the 1980s. In earlier decades, the entities now described as Nordics were often called "Space Brothers". Some of the best known individuals who claimed to interact with Space Brothers include George Adamski and Howard Menger. However, these men's stories are widely considered "absurd hoaxes", in the words of Jerome Clark.
David J. Skal says that early stories of Nordic-type aliens may have been partially inspired by the 1951 film The Day the Earth Stood Still, in which an extraterrestrial arrives on Earth to warn humanity about the dangers of atomic weapons.
Stephanie Kelley-Romano observes that "white extraterrestrials are those that are most revered", compared to other beings like the greys, and argues that claimants may use their stories about extraterrestrials "as a means of articulating racially based fears".