Abraxas was a grotesque creature with a twin tail – similar to the twin tailed mermaids known as “melusines” in the Middle Ages. It appears on Templar seals and was presumably a cult picked up in the east as Templar knights went to fight in outremer. The origins of Abraxas seems to lie in gnostic beliefs in an overarching deity more powerful than all other gods.
Abraxas seems to have played a central role in the gnostic cult of Basilides in the second century AD. This Alexandrian mystic was teaching at a time of huge religious ferment when Christianity hadn’t completely defined itself in the way that we know it today. So Basilides did believe in a kind of disembodied Jesus – gnostics didn’t like the idea of an incarnated God – and that the only way to know Jesus was through a process of intense meditation, for want of a better word, called ‘gnosis’. How Abraxis fitted in to this is probably as some kind of master-god above other divine and semi-divine entities. Happy to have that explained more accurately by experts out there.
The head of Abraxis sometimes resembles that of a Basilisk – the cockerel crested serpent head of that legendary beast. The trunk is normally that of a man and then legs of snakes and feet which seem to resemble scorpions.