The general consensus is that theoretical fractals are infinitely self-similar, iterated, and detailed mathematical constructs having fractal dimensions, of which many examples have been formulated and studied in great depth.
Like this rich color scheme
The head of Romanesco broccoli is a striking example of an approximate fractal in nature
A fractal ocean splashing on the shores of eternity. http://johnpirilloauthor.blogspot.com/
Physarum polycephalum / Slime Mold
Leaf, exhibiting both fractal spiral & branching patterns