The fire mutation is expressed as a subtle colour and pattern variation. These snakes are lighter than normal individuals, with uniform, straw-coloured sides. Their pattern aberration is characterized by stretched and distorted 'alien heads', which often stretch up and over the spine. Fire ball pythons typically have a head spot and some degree of fading in the black areas over their spines.

While this mutation may seem unremarkable at a glance, it shows its true colours (or lack thereof) when expressed in its homozygous form - the stunning black-eyed lucy (leucistic).