You might consider using a biomorph algorithm proposed by Dawkins. It essentially uses a evolutionary process to search large configuration spaces to produce desired shapes. For example the following generalization of the Mandelbrot.
The varibles

are free parameters. At each selection step you produce 8 or so new sets of parameters which are slightly varied from the original, then render all them all along with the original. Pick the one that you like best and re-iterate.
The second order Mandelbrot is probably not varied enough to produce the desired image, but you can alway go to higher powers. Throw in some trig functions etc.