Hi hoola,
Yes - the fluid isn't from a tweeter, although that's a good guess. I actually tried to make a ferrofluid out of the ink, but was unable to get the iron powder into solution without totally changing the colour. I also tried iron oxide which is a closer match to the red colour of the dragon's napalm ink, but it seems to be only weakly ferromagnetic. So the spiky version of the ink drop is just iron power stirred into the ink which lifts the ink up around it when exposed to a magnetic field. Not as elegant as an actual ferrofluid, but it worked in a pinch. I used a stack of five small rare earth magnets to manipulate the "puppet".
The skating effect was achieved by treating the paper with a hydrophobic spray.
Thanks for watching!
Cheers,
NF