Tangela could be the hardest common Pokemon to find. first, either migrate from gba game, or wait until there is a tangela swarm(sinnoh now or Dawn/?????'s little sister in sandgem town. Then make sure you have a heart scale, go to the great marsh plce, where wke is, go to move tutor, teach tangela ancientpower, level it up and you now have a tangrowth! it evoles when it learns ancient power!!!!! (then level it up)