You can find find LV.0 or LV.80 or LV.184 Missingno's. He has VERY low defense. If you do want to catch him, he knows Water Gun, Sky Attack, and Water Gun again. Yup, 2 Water Guns. You can catch him adn then after you do, an invisible one will still be there. The invisible one evolves into Ditto. The first one evolves into Kangaskhan. Feed a Missingno a rare candy and it will evolve into a Ditto or a Kangaskhan, depending on which one you caught. Missingno can learn Strength, Fly, and Surf. So you could have a flying, surfing Kangaskhan or Ditto.