Certified GKH Gardening Expert
It could be slime mold. Slime mold takes many forms. The most common forms on grass resemble small purple or black balls attached to blades of grass but you may also see white to yellow‑orange, jelly‑like masses in lawn areas too.
Slime mold, for the most part, is a beneficial organism that decays dead plant material, returning nutrients to the soil. It is not a disease, but grass that has slime mold growth may be more susceptible to turf diseases, especially if humid conditions are common.
Chemical control is usually not necessary. Raking up and disposing of the slime mold is usually all that is required, or it will go away on its own during warm, dry conditions.