Olive is one of those kinds of characters in comics that villains throw at the heroes who have all the powers of their foes, like the Super Skrull or Amazo. Her name comes not only from the tone of her fur/skin and the fact that she is on of the Mean Green Witch's "Green Creatures", but also from an old joke where kids have been supposedly known to have mistaken the line in the Rudolph song, "All of the other reindeer..." as "Olive the other reindeer..." So, there you have it, "Olive the Evil Reindeer!"
Ha-ha, even green reindeer chicks can be sexy in their own way, huh? As, to your other comment, yeah, she certainly does, yet it just makes her a more interesting and complex villainess.
She's quite sexy for a green reindeer. Wait, what the hell kind of sentence is that? Cool villain. I honestly feel kinda sorry for her -- girl has issues.