Updated: Jun 19
“Slime mold” is a nickname for a group of organisms that can live freely as single cells or fuse together to form multi-cellular organisms with reproductive structures, exemplified here. Globally there are between 500-900 species of slime mold and they are found in every color of the rainbow except green.
Slime molds are not fungi, but I like to refer to them as "friends of fungi" because they share the same habitats. These organisms feed on dead plant matter and are most commonly found on forest floors. While both slime molds and fungi reproduce using spores – and were formerly assumed to be associated with each other – they are no longer considered to be related and are presumed instead to be a type of soil-dwelling amoeba.