"Piggybacker"
An unspecified species, referred to by Lizzie Dalton as "piggybackers", were psychic creatures with no physicality. From parts unknown, they used a host to command silent slaves (who's mouths would literally disappear when controlled), who turn the invaded planet into temples dedicated to themselves. Some species', such as that of Hank, Lizzie, and Tommy Dalton, were immune to their powers. Instead, the piggybackers hunted and slaughtered their kind for generations.
One particular piggybacker found a host in Edith Harcourt, a teacher at Brideport Elemenatry School in the United States, that used her seniority to command a legion of younger slaves.
Severing ones connection to a piggybacker resulted in the death of the host. (COMIC: The Piggybackers)