Channeled by Barbara Marciniak in the New Age classic, Bringers of the Dawn, the Pleiadians present themselves as a group entity from the far future.
The book is addressed as a wake-up call to supposed "wanderers", or "system busters" who have incarnated on Earth at this time to assist with the events of the Wave. The book is engaging but, according to the FotCM take on the matter, it is a mixed source with genuine higher density information blended with the channel's preconceptions and a heavy dose of "you create your own reality".
The term "lizzie" was first introduced in Bringers of the Dawn as a name for the 4th density STS overlords keeping humanity captive. The book agrees in many key points with Cassiopaea and Ra and is a good read if one does not take everything too literally. Marciniak's later work is, in the FotCM view, rather more STS-influenced and ritualistic, thus Bringers of the Dawn remains her best work.
The Cassiopaeans have said that Ra and the Pleiadians are their "colleagues", occupying a somewhat different point of focus in sixth density but with access to essentially the same understandings. Differences in the channel and audience can account for many differences of focus and tone.