Question

What might an envious charcter do

Answer 1

A envious character will get even

Answer 2

The definition of envy is jealousy or covetousness.Being discontent or resentful because of what someone has.

That added word resentful adds a slightly heavier tone than jealousy because like covetous person you are most likely willing to take steps to take what you want from someone so that they get harmed/hurt or are deprived of something they want or need.You didn't list any options with your question so in general:
 
an envious character will do anything from kill a loved one of the person they envy, sleep with their wife, steal money,cars,heirlooms all so the person they envy is deprived. They may even try to destroy that persons quality of life or livelihood. Basically any action that takes something away from the object of their envy. Hope that helps.