Paper fractals are fascinating self-repeating/reducing designs that are relatively new in the origami world:

This 2nd-level “Octospiral” is a model I saw in one of my last BOS journals before my membership lapsed. Designed and modified by Roman Diaz, Endre Somos and Meenakshi Mukerji, it is a delightfully dense spiral that, theoretically, could keep reducing inside itself indefinitely.Naturally paper, fat clumsy fingers and accuracy become the enemy when trying to take this smaller – I started with a 35cm nearly-square of washi and innacuracies crept in even at this level. A greater accuracy would be needed to take this further. Fun fold none the less, and nearly caught up – yay.