Hey /vp/, I need some help figuring out the grass starter for my fangame, here our the other starters so far.

Water: Crab->Evolves into a Mecha and Crab combined, and is bipedal at final, first evo doesn't change much from the unevolved stage.
Fire: Rabbit(bipedal)
Grass: Starts out bipedal, and becomes quadruped at final stage.

I want them to be like this because I kinda wanna form a pattern, as in each gen there is always two bipedal starters and one that is quadruped to make you understand more. Now I need a animal or something to represent the grass starter, any ideas.