But Hellquist hasn't finished. Fro, believe it or not, is also cognate with "frog", Sw groda, a word apparently obscurely related to Sw groda, not a million miles from English "growth". For the divinity of frogs and toads see Marija Gimbutas: illustrations below. Prehistoric biologists, embryologists and natural scientists would have observed that frogspawn and toadspawn rapidly convert into tadpoles, eggs with tails and sprouting legs, all of which can be seen, without the aid of a microscope, as growth from various sorts of seed. Fro survives in English as "fry", as in "small fry", little fishes, especially those fresh from the spawn, or little children.
From Hel to Hell and Back