Slime molds are a fairly well-known grouping of organisms, performing a valuable function as real-life detritivores and bacterivores, as well as inspiring fantasy tropes such as oozes. Many slime molds will generate fruiting bodies, as well, in order to distribute their spores (think mushroom), and in a few cases, smaller animals (such as slugs) eat them. Under what conditions on an Earth-clone could a slime mold which had some human-edible parts evolve? It doesn't have to be the entire mold as that'd be hard to gather, but am I correct that a slime mold could produce a fruiting body you or I could pick and eat?
Under our conditions
- Enteridium lycoperdon happens to be eaten.
- There are rumors on Chinese cases of eating unspecified kinds of them
So it seems that indeed, some of them produce a fruiting body you or I could pick and eat.
Of course, stronger references would be nice, but I couldn't find any.
There is algae that is healthy to eat and alive, maybe this algea binds together in clumps and moves the mass as a unit. They could have spun off a new evolutionary branch in order to migrate between water sources in a highly aquatic environment, but the water separated by thin strips of land.
Or, they could also be eggs of some creature that move around in their eggs like spiders do. Moving somewhat random, but moving nonetheless.