His eyes glow ghoulishly in the right light, just like any other cat's - but so do his nostrils, gums and tongue.
Mr Green Genes of New Orleans in the U.S. is the country's first 'glow in the dark' ginger tom.
In daylight he looks normal, but put him in a darkened room and switch on an ultraviolet light, and his face will beam out a bright green.
The six-month-old cat was created by scientists who are trying to combat a range of diseases such as cystic fibrosis.
They modified his DNA to see if a gene could be introduced harmlessly into an animal's genetic sequence.
To track where the gene went, they decided to use one that glowed under ultraviolet light.
The particular gene in question, known as green fluorescence protein, is likely to express itself in mucous membranes - hence his freakish mouth and ears.
Betsy Dresser, at the Audubon Centre for Research of Endangered Species in New Orleans, said the gene that was added to Mr Genes has no effect on his health.
She said: 'Cats are ideal for this project because their genetic make-up is similar to that of humans.
'To show that the gene went where it was supposed to go, we settled on one that would glow.'
The long-term goal of this project is to develop what has been dubbed a 'knockout gene' to combat the cystic fibrosis gene and other diseases.
The fluorescence gene will go alongside the cystic fibrosis gene and make it easier to spot for scientists.
The Nobel Prize in Chemistry was this month awarded to the three scientists who had discovered the glowing gene through working with jellyfish.