You can Tribute 1 "Eva Token" to Special Summon this card from your hand. While this card is in your Graveyard, each time a monster(s) your opponent controls is removed from play, Special Summon 1 "Eva Token" (Fiend-Type/DARK/Level 2/ATK 500/DEF 500).
In some, really most languages & cultures, Fairies or Fae are considered Gods & come in many shapes, forms, even alignments. Mermaids, Angels, etc. all are considered Fae. So giant Scorpion with the power to summon(create) nearly monster in the game? That's some godly magic right there.
Zeta though... maybe its a tie into Human Evolution. In Christianity, Eve or Eva was the 1st Woman, like the other anon said, who eventually had her 1st set of children after being banished from Eden. ...so actually, yea, I think Zeta here is reminiscent of the Biblical Eve. Her Adam though? Idk, but both Serket & DD Crazy Beast make excellent partners.
RE:you have one in the grave and one in your hand. remove from play an opponent monster the one the grave will give you an token you then SP summon the one in your hand or use Monster Reincarnation yo get it out of the grave (if you only have one copy )after you get your token