Clefairy and Clefable, Mew, Togepiand Togetic, and Munchlax can all learn Metronome by leveling up.
MetronomeClefairy, Clefable, Mew, and Mewtwo can learn Metronome.
i have two Pokemon from Pokemon fire red/leaf green and togepi/togetic and gengar can learn metronome
Any Pokemon that can learn a electric move
Yes.
I don't know all of the Pokemon that can learn Headbutt, but I know that Cubone can learn it.
Electivire cannot learn Volt Tackle in Pokemon HeartGold. Only pichu, pikachu, and raichu can learn volt tackle.
No Gastly cannot learn fly in Pokémon HeartGold.
No
Bayleef Does Not Learn Sleep Powder in HeartGold/SoulSilver
Do you mean what Pokemon can learn Flash? Bellsprout can, and I think Togepi can, too.
Snorlax does not learn hypnosis.
Clefable does not learn Metronome via leveling up. In order to get metronome you must have Clefairy learn it at lvl 31, then use the Moon Stone to evolve into Clefable. In Generation I (Red, Blue, Green and Yellow), you can, however, teach Clefable Metronome from TM 35. TM 35 is obtained at the Pokemon Research Lab which is the building just south of the Pokemon Mansion on Cinnabar Island.