A growth hacker is likened to a product given from the chemical reaction of two elements; marketing and engineering. They are like a super-mutant of the Internet era. Instead of traditional marketing, which typically breaks the continuity of your day, a growth hacker understands user behavior to persuade, through the value it immediately provides.
This infographic by GrowthRocks.com outlines what a growth hacker is, as well as his skills, tools and attributes.