You're right, diotalevi, it is a fractal. Good eyes! Specifically, it's a Lindenmayer system (L-system) type of fractal. A definition of this type of fractal is:

"A L-system or Lindenmayer system is a formal grammar for generating strings. (That is, it is a collection of rules such as replace X with XYX.) By recursively applying the rules of the L-system to an initial string, a string with fractal structure can be created. Interpreting this string as a set of graphical commands allows the fractal to be displayed. L-systems are very useful for generating realistic plant structures."

The above definition comes from this FAQ.

I just recently started reading about fractals, and since this type is string-based, I thought it would be fun to try it out with Perl. The starting shape that I used looked something like this (please excuse the ASCII art):

***  ***
  *  *
  ****

Hope this helps, and thanks for the comments.