In the relaxor ferroelectric Sr0.8Ba0.2Nb2O6 (SBN80) the relaxation of polar nanoregions (PNRs) reveals an anisotropic breathing mode when approaching the transition temperature, TC ≈ 289 K, on cooling. Two distinct dispersion steps and peaks, respectively, of the complex susceptibility components in the milli- and megahertz frequency range reflect their large length-to-width aspect ratio. Below TC power-law frequency dispersion characterizes the creep motion of the emerging ferroelectric domain walls and the fractal dimension D ≈ 2 of their contour lines. Piezoforce micrographs reveal nanometric jagged domains in accordance with the large disorder and random field magnitude in the extreme relaxor SBN80.