This one looks sort of like a shuriken or throwing star. It was synthesized by repeatedly building a line fractal and doubling the number of arms.

For a general method that forms a line from a Mandelbrot set fractal see Line Method.

The parameter file used to make the image:

Shuriken { ; Exported from Fracton.
 ; time = 14 min 48 sec at 640 x 480 with no aa
 ; on a Mac Pro 2 x 2.8 Ghz Quad-Core Xeon
 ; by Mike Frazier, public domain
 reset=2004 type=mandel passes=1 float=y
 center-mag=-0.637200976755101990090375751704920316\
 4129285920553172950221050123642148620218915862204/\
 -0.49499504293951702730512003147598679071318907247\
 67733511982230245678938692912016518461/1.302083349\
 609375e+75/1/-21/0
 params=0/0/0/0/0/0/0/0/0/0 maxiter=16000 inside=0
 proximity=0
 colors=000y_TxZSuYRsXQpVOlSNhQLcNJZKGUHEOEBIA8C756\
 32000411932E54J75N87RA8VB9ZDAaEBdFCgGDiHDjHElIElIE\
 mIFlIElIEjHEiHDgGDdFCaEBZDAVB9RA8N87J75E5493241100\
 0310721A32E42H53K64N74Q85S95VA6XB6YB6ZB7_C7`C7`C7`\
 C7_C7ZB7YB6XB6VA6S95Q85N74K64H53E42A32721310421942\
 D73I94MB5QD6UF7XH8_J9bKAdMBfNBhNBiOCjOCjPCjOCiOChN\
 BfNBdMBbKA_J9XH8UF7QD6MB5I94D739424210002414927E39\
 J4BN5DR6FV7HZ8Ja9KdAMgBNiBNjBOlCOlCPmCOlCOlCNjBNiB\
 MgBKdAJa9HZ8FV7DR6BN59J47E349224100022644C77I99OBB\
 UDDZFFcHHhJJlKKpMMsNNuNNxOOyOOzPPzOOzOOyNNxNNuMMsK\
 KpJJlHHhFFcDDZBBU99O77I44C226000641C92IE3OJ4UN5ZR6\
 cV7hZ8la9pdAsgBuiBxjBylCzlCzmCzlCylCxjBuiBsgBpdAla\
 9hZ8cV7ZR6UN5OJ4IE3C92641000413937D5AI6EM8HQ9KUBNX\
 CQ_DSbEVdFXfGYhGZiH_jH`jH`jH`iH_hGZfGYdFXbEV_DSXCQ\
 UBNQ9KM8HI6ED5A937413000632C75IA8OEBUHEZKGcNJhQLlS\
 NpVOsXQuYRxZSy_Tz`Tz`Uz`T }