That means if 2 frogs (middle and one outer) jumped, then the weight distribution of the last remaining outer frog would have been too much, therefore tipping the lily pad off balance and throwing the remaining frog into the water. That was the easy explanation.
Medusa first appeared in Fantastic Four #36 (1965), and was created by Stan Lee and Jack Kirby. She appears first in flashback, then in costume as part of the fledgling Frightful Four. She appears in #38, 41, 42, 43, 44-48 and in various subplot glimpses from #49-62. The Inhumans also appear in Fantastic Four # 82-83, with Medusa.
Countless texts illustrate Medusa's affinity with the depths of the sea and the terrible power of nature, e.g. Hugo's Les Travailleurs de la Mer (1864), LautrÃ©mont's Chants de Maldoror (1869) and Pierre LouÃ¿s' Aphrodite (1896), but the most explicit example is probably the text written by Freud in 1922: Das Medusenhaupt -- 'Medusa's Head'.