The Cabbage Looper is the larval stage of the moth Trichoplusia ni. It is a major agricultural pest, feeding by night on cabbage and related plants, like some sort of wormy goth polack.
Physically the animal resembles an inchworm, lacking any limbs in the middle of its body. Its locomotive process is similar. The Cabbage Looper is about 1 inch long and green in color with the larval equivalent of white racing stripes down each side.
They pupate in a silk cocoon attached to the underside of a leaf (watch your salad carefully), and emerge as a brown moth with white spots on each wing.
The little beast lives everywhere from Canada down into Mexico, infesting and destroying crops of cotton, potatoes, spinach, soybeans, lettuce, celery, parsley, tomatoes and several valuable flowers.
They are normally controlled though use of bacterial agents.