Although when you think about it, it's probably still a monad
Didn't get the joke?
Mereology is the study of how parts relate to their whole. Mereological Nihilism, the view expressed by the monster, it is the belief that there is no "whole" per se, only the parts actually exist. So, for example, one might say when looking at a chair that no such "chair" exists, the "chair" is only an idea in our minds - all that really exists is a collection of atoms. Similarly, there would be no "you", only the atoms that your body contains.
Élan vital is an outdated scientific and philosophical theory of a "vital force" that gives life forms their animation. It was supposedly what distinguished between living and non-living things, and was linked with motion and consciousness.