Hi,
Often called “Star Jelly” it’s probably unfertilised frog spawn.
from the RSPB spokesperson
“If the animal is attacked by a predator β herons for instance are fond of the occasional frog β it will quite naturally drop its spawn and the associated glycoprotein. This is designed to swell on contact with water, which gives the gelatinous mass we are all familiar with in frog spawn. However, if itβs unfertilized, it is just the empty glycoprotein that is dropped β which on contact with moist ground will swell and give a clear, slime-like substance. “