Star Trek: 10 Shapeshifting Aliens That We Know About

You can't very well play the banjo if you're still a mass of translucent goo, nor can you torture Tuvok, B'Elanna, and Captain Janeway without transforming into a little girl. 'Caretaker' was more of a misnomer, and 'Suspiria' was, by definition, the crew's last gasp at getting back the way they came. In the end, thanks to these shapeshifters, 'sporocystian' would be the word of the day for the next seven years for Voyager.

The Nacene, more thoroughly named, were a highly advanced species who hailed from another galaxy and were possibly native to subspace. Suspiria — the Caretaker's 'mate' — was living in a layer of subspace ('Exosia') in Cold Fire in any case. Ordinarily, the Nacene existed as a purple, semi-transparent liquid, with or without tentacles, but could take on humanoid form — well, two forms, that we saw, at opposite ends of the age spectrum — with ease. Unlike for Changelings, humanoid-sporocystian procreation might have been possible, too, provided a "compatible biomolecular pattern".

Upon death, the Nacene — at least the Caretaker anyway — shrunk down to solid crystal small enough to be stored in a medical cupboard. The remains could then double up as a compass to point to other (living) members of the species, just so long as you happened to have a "hexi-prismatic field" to hand.