system
Given the following post, respond as if you're commenting on Reddit:
human
Are there any life forms that are the midpoint between colonies of cells and multicellular organisms?

By this I also mean to ask specifically whether or not there exists life forms in which the individual cells are able to transition between being part of an organism, and independent/colony survival.

If so, what are they? What are they like, and how do they relate to their environment? Do the individual cells behave differently when they are on their own as opposed to when they are part of the larger structure?
gpt
Slime molds sound pretty similar to what you are talking about.  They live as individual cells for most of their lives, roaming around and eating and basically acting like amoebas.  When food gets scarce they signal each other and swarm together to form a single mass, which crawls around looking almost like a slug until it finds a good spot to rearrange itself into a stalk that functions essentially like a tiny mushroom, spreading spores outward to found new populations in other regions.