Ferrofluid is a very special liquid that is magnetised when brought into the presence of a magnetic field.  The Ferrofluid created wild, spikey shapes and patterns as it is in close proximity to a magnet. Most pictures of Ferrofluid depict it with a very ‘spikey’ shape which is caused as the ferrofluid forms the most stable shape it can to minimise the total energy of the system, this is known as normal-field instability.