How to present Tabitha

It has been too long since I posted something, but I have been struggling with the cover image. There are a number of frogs in the novel, and they figure somewhat prominently in the story. Since frogs are somewhat naturally humorous, I figured a frog image on the cover might work. But trying to find the right frog -- well, that is another matter altogether. Too cute, too serious, too -- what does this have to do with anything? So I guess I have to ask myself -- how do I want to present Tabitha, my main character? She is smart, sassy, twisted, vulnerable, and devious -- ultimately human. She is a compulsive listmaker, an impassioned lecturer at the university, a non-conformist. While frogs enter into her life in an unusual way, linked to another character who is an expert in cryogenics, should they really be on the cover? How much should the cover image relate to the book itself, and how much should it be understood as a marketing tool. I will ponder these questions over the weekend, and see what I can come up with. I have had a number of good suggestions from friends and graphic designers, but of course what is obvious is that everyone has a different sense of the book, and ultimately, I am the one who must make the decision. Ribbet.