Read more here.Pokédex entries on Oddish focus on two aspects: its ability to walk and its scream when pulled out of the ground. (Entries on its evolved forms Gloom and Vileplume reflect those creatures’ real-world inspiration, the notoriously foul-smelling Rafflesia flower, and thus focus on secretions, odors and toxic pollen.)
The former is nothing unique in the world of Pokémon. The original 151 include a number of walking plants or hybrid plant-animals, including the Bulbasaur family, Exeggcutor and Tangela, which inexplicably wears red shoes. Its scream, on the other hand, points back to a plant, both real and mythical, which was planted in the human imagination many centuries ago and has never been fully uprooted.