I'll ruin the Captain Obvious mood for you then.
Poison Ivy was always my favorite villain and in high school people used to call me that (along with Spock, but that's for entirely different and surprisingly non-nerdy reasons) because I was always growing plants and talking about killing all humans, etc. In college I stepped up my world domination plans and continued growing plants in my dorm room, but specialized in the poisonous ones and had quite a lovely garden of foxglove, hemlock, and belladonna. At some point in my freshman year I started playing some mobster RPG and picked Ivy Da Plant as my mobster name. A week later I was IvyThePlant online and I've been that ever since.
So despite what my Crazy Ex Neighbor says, I never copied her by picking the name Ivy. I was Ivy while she was being deported from South Korea for drug trafficking in the US embassy.