Bulbasaur, Charmander, and Squirtle
Chikorita, Cyndaquil, and Totodile
Treedy, Grilpas, and Kanew
Grassy, Firey, and Watery
Treecko, Torchic, and Mudkip
It makes the Pokémon with Levitate faster due to flying capabilities.
It helps you avoid wild Pokémon because you can float over them.
A Pokémon with Levitate is not affected by ground-type moves regardless of the Pokémon with the ability.
Levitate makes the moves "Fly" and "Bounce" stronger due to the ability to go to higher altitudes.
Both of them will do the same amount of damage.
Raichu can't learn dig.
The nature of a Pokémon increases one stat by 10% and decreases another by 10%.
It will affect the behaviour of the Pokémon in the game.
It will have an effect on the Pokémon's happiness.
Nothing. It is just a cool thing to have.
Missingno. can only be found by glitch or cheat.
Missingno. can look like a ghost, a strange Kabutops, or a ghost (In Pokemon R/B)
Missingno. will glitch up your save data and possibly the whole cartridge when caught.
Missingno. is not the only glitch Pokémon.