Its English name is made from the words Venus (or Venus Flytrap) and Dinosaur, yielding its name, Venusaur.
Venusaur is unfortunate because he's the one no one wants. Charizard or Blastoise please. Venusaur's a reject. Apparently, Nintendo noticed this when they were bringing Red and Green to America, so they kicked Venusaur right out of there and had Blue be one of the two games instead.
So kids, the next time you use a Venusaur, give him a hug, he needs it.
Venusaur evolves from Ivysaur starting at Level 32.