I've decided a good place to start for a new direction with pokemon stuff is the middle-stage pokemon.

We fall in love with their first form, and pine for their final evolution, but the second stage gets so little love. Honestly, I always got the vibe that the middle stage is the state that most pokemon will spend their lives in- that evolution is an extraordinary phenomena that just highlights how special the trainer-pokemon bond.

As for Ivysaur in particular, I've always really liked it. It reminds me of an "Ugly" but intriguing dog breed, and the expression its given in concept art is always that of an alert intelligence. Also, that gen one bipedal sprite...