Clip-on cat ears which fit on most generic wide plain hairbands found at drugstores, grocery stores, etc.
The two-color effect was just achieved by pausing the print and changing the filament. The color used was "Helsinki Sky" from Makerbot.
As seen on ABC's BattleBots (Sunday 9pm / 8pm Central)
Most likely requires support for the clips to print correctly and due to the angles. Prints in the supplied orientation okay for most printers. Tried on a Replicator 1 and Up Mini.
Some hand-filing to fit may also be needed.