I had a flurry of inspiration the other day.
These are just rough concepts and I may not take any of them any further.
If anyone is inspired by any of these then please, run with it.
Pollution elemental
City elemental
Network elemental
Light elemental
Sound elemental
Gravity elemental
Hair elemental
Space elemental
Time elemental
Good stuff indeed!
I had been mulling over a couple myself...the core of the question I tend to see as more fundamental...with actual elements...fire, earth, air, water, metal...specific elements as per the periodic table...but I also like to play with the box as I look outside of it.
Trash/garbage elemental...as a character I could see this one as a cloner...making copies of its human form (identical) in a classic mundane hobo with a shopping cart, pushing it through the city collecting the throw offs of society one bit at a time...when he needs to act his clones fall away into equal volume/mass of random garbage and forms as a massive flowing humanish shape to the point drawing its focused attention...

This could be a fun one as a benign protector of the inner city...leaving collectable toys/items found within the daily garbage for the orphans, homeless children, and others in need to cash in for a better life...reclaiming tools and related items for the same in stress adults to use for work or sale...as a creature that never sleeps, able to spread itself into many clones, constantly searching through the easy to access as well as the deep mounds of garbage it could find items that have significant value, especially when collected together like precious metals, jewelry, gem stones, etc.
I could see this character as a fairly emotionless modern man made force of nature with a driven to collect and recycle...in the end leaving neat spheres of like materials...compressed paper, cloth, wire, glass, plastic, etc. the organic materials being compressed into balls of pure fertilizer.
The despair and anguish of those in pain of need, those mentioned before, would draw its attention and give direction until the moment had passed...a child crying in the shadow of building because they are hungry and cold...a quiet raggedy man pushing a shopping cart comes into view and gives the child a collectable lunch box filled with treasures...an old GI Joe, a diamond ring, a rolex watch, a roll of random paper currency, and lots of coins...and just as silently and quickly the raggedy man is gone.

For comicbook context, this character would react to evil just as it does to a child's hunger...a flowing wave of garbage enveloping a rapist before he can complete his intended action, the foul desire drawing the elemental in like a beacon, smothering the criminal unconscious and depositing him on a well lit street corner...covered in the less appealing aspects of what can be found within garbage...a slime of stink...marking the evil doer for others to find and know why he was left behind.
A supervillain fighting superheroes would draw the elemental in and cause it to act, not so much as being part of the team but because the bad guy radiated active evil.
