Actually, I believe that "Envy" as such is something easily portrayed by many creatures. Technically, you could believably put that tag on any monster, if you tell the story well, you can even have them embody the sin itself.
I take one of my stories as an example (as I often do, because of those I understand the intentions behind certain characters best): There's a thing that Divine Beings can become gods, but once above a certain threshold in strength, even demons will turn into Gods. One of them was Jormungandr, who in this world has been mixed with Lucifer and his biblical origins, and in the backstory I wrote down years ago, because the writing of this story was put on hold during a long non-writing / writer's block phase, I put him among the seven Gods of Calamity into the position of representing Lust. But that was choice I made for the reason of convenience. Backstory wise, Envy would have fit just the same. The reason for that being the fact that he had looked at all the people, being shunned by his father (a High tiered God from Araphel) as the child he had with a demon, being locked away at the bottom of the ocean. His ability later turned out to be changing his appearance, seeking human touch and warmth (that's why Lust was chosen), but all those years he was envious, sad and lonely, watching what he couldn't be, yearning for things he couldn't have, which the humans he was watching could obtain so easily (thus evolving into a God, shaping the ability to change, in this case, not just face and gender, but in the first place from a snake into a person). Here, the snake is also fitting both envy and lust in the imagery.
Also a good example is the one actually chosen as envy, because she seems more angry most of the time, but the reason she's envy is because she was the first human to rise to become a God, by dying and becoming a demon. And Envy was what caused her death in the first place. That fit my story, but it just as much fits any, I believe. In this case, it's a specific backstory, not the being itself that is associated.