Axanthic Chocolate Anaconda is a combination of the recessive swiss chocolate mutation, the recessive axanthic mutation and the heterozygous incomplete dominant anaconda mutation. The swiss chocolate gene creates a darker headstamp due to the higher concentration of melanin on the head. The anaconda mutation removes some of the dorsal pattern. As the snake ages, the snake either becomes an almost black snake with a darker headstamp or it becomes lighter coloured with a grey-blue hue and dark grey saddles. Females are often very dark and males are often lighter in colour.