So, first things first, I did some more thinking on Gluttony and how its enormous mouth ought to work:

“Like a serpent or shark, Gluttony’s jaw is only loosely connected to the rest of its skeleton, allowing it to unhinge and devour large amounts at a single gulp; as opposed to Leviathan’s multi-hinged jaws.”

Next, I had been thinking about the differences between Greed and Envy on and off through the day, and this is what I came up with:

Greed (as defined by me):
-Wanting more of what one already has. (wealthy) confident or a bit paranoid (not as materially secure.)
-Selfishness, avarice, holding on to possessions.
-Cheating swindling or otherwise exploiting in the name of material gain.

Envy:
-An all-consuming need to have what others have, it’s jealousy on overdrive.
-it is selfishly motivated but ares little for having more, it is covetous, not materialistic the way Greed is.
-It is a cousin of shame; the idea that being like another will validate oneself.

They are similar, but Envy is smaller with larger eyes to see things to covet. It should probably have larger eyes than Gluttony.

So now that that distinction has been made:

Greed

As described in Wikipedia:

Greed (Latin, avaritia), also known as avarice or covetousness, is, like lust and gluttony, a sin of excess. However, greed (as seen by the church) is applied to a very excessive or rapacious desire and pursuit of material possessions. Thomas Aquinas wrote “Greed is a sin against God, just as all mortal sins, in as much as man condemns things eternal for the sake of temporal things.” In Dante’s Purgatory, the penitents were bound and laid face down on the ground for having concentrated too much on earthly thoughts. “Avarice” is more of a blanket term that can describe many other examples of greedy behavior. These include disloyalty, deliberate betrayal, or treason, especially for personal gain, for example through bribery. Scavengingand hoarding of materials or objects, theft and robbery, especially by means of violence, trickery, or manipulation of authority are all actions that may be inspired by greed. Such misdeeds can include simony, where one attempts to purchase or sell sacraments, including Holy Orders and, therefore, positions of authority in the Church hierarchy.

As defined outside of Christian writings, greed is an inordinate desire to acquire or possess more than one needs, especially with respect to material wealth.

Greed:
-Long Jaw for grabbing and holding.
-Almost confident “smile” from mouth shape belied by eyes (small, wary)
-head fins smaller than Pride, larger and more numerous than Envy.

Last, I had hoped to do Sloth tonight as well, but while mulling it over, it occurred to me that Sloth is not just being tired and/or slow, it’s something more akin to indolence, which doesn’t work with the turtlelike appearance I had started with, though the symbolism is still there. Sloth is not falling asleep at your desk at work; it’s deliberately wasting time at work doing something like looking at lolcats. The ecumenical definition goes a step farther, but that’s something that will have to wait for tomorrow.