OK, you're not in Flash Freeze, you're in Iceconoclasm. (The Ice pick and Escape rings were in the previous level, Flash Freeze.) You can get up the spike walls with one (or both) of two spells -- the Tree Trunk spell, which you probably already have, and the Ice Wall spell, which you might have missed. Although some people say that Tree Trunk is easier for getting up the spiked walls, I think Ice Wall is easier and I wouldn't go any further in the game without it. You can find instructions for getting Ice Wall elsewhere on the board, or post again if you want a spoiler.
PS. I hate the frogs, too, more than any of the other enemies!