Chlorofiend

The Chlorofiend is a plant monster and type of faerie. It appeared in Summer Knight.

Description
The Chlorofiend is a magical construct that took the form of a plant monster.

It had a vaguely human shape and was made of earth, root, and bough. It had two emerald-green lights in its head of writhing vines and leaves. It was about nine or ten feet tall and almost that wide. Its legs were as thick as a person. There were branches that stuck out like horns. Its scream sounded like tortured wood.

As a Faerie, it is sensible to iron and steel.

Originally called a plant monster, Harry decided it didn't seem right and used a term he heard Bob use.

It was part of a team of faeries that attacks Harry and Karrin Murphy, including Mind Fog, Grum and the Tigress.

Summer Knight
In Summer Knight, at a Walmart where Harry Dresden and Karrin Murphy met to discuss his case, it emerged out of a pile of plants in the garden section and trees slowly while branches twined around Harry's ankles and hauled him up-side-down in the air as he watched it take shape.

Harry Dresden fought it surrounded by Mind Fog. He used an evocation to call up wind that trew heavy steel shelve onto it, taking it out of the fight for a while.

When Dresden returned to the Garden center, the fence was covered in frost where it had been cut and the Chlorofiend was missing. It attacked again in the parking lot, bringing its fist down on the Blue Beetle, then Dresden proceeded to bash it with the Beetle—made of iron, not fiberglass. It grabbed Harry and tried to pull him apart. Murphy got him with a chainsaw right between its eyes.

Later, Aurora admitted to sending the plant construct to kill him.

Quote
"'Meddler. You should never have involved yourself in these affairs. You have no concept of what is at stake. Die for your arrogance.' ~ Chlorofiend"