Level 13
a healing move
Softboiled can be used outside of battle in all versions and can be used to take away some of Chansey's Health Points in order to heal another Pokemon in your party. Remember that the Pokemon will be rehealed only by the amount of HP taken away from Chansey (Or any other Pokemon using softboiled).
All Pokemon with a water-type can learn it. There are some other Pokemon that can learn it, but mostly water-Pokemon.
I don't know all of the Pokemon that can learn Headbutt, but I know that Cubone can learn it.
Softboiled is a move that allows a pokemon to restore half its hp
Level 13
a healing move
Softboiled can be used outside of battle in all versions and can be used to take away some of Chansey's Health Points in order to heal another Pokemon in your party. Remember that the Pokemon will be rehealed only by the amount of HP taken away from Chansey (Or any other Pokemon using softboiled).
soft boiled is not a move.
Soft-Boiled is the signature move of Chansey and Blissey. However in FireRed and LeafGreen you can teach Soft-Boiled via a move tutor to Clefairy's evolution line, Togepi's evolution line and Mew.
You can only do this once one of your Pokemon has learned surf at the safari zone. The man teaches the move softboiled which regains health.
All Pokemon with a water-type can learn it. There are some other Pokemon that can learn it, but mostly water-Pokemon.
Pokemon cannot learn Yawn in Pokemon Silver.
at level 12
I don't know all of the Pokemon that can learn Headbutt, but I know that Cubone can learn it.
Any Pokemon that can learn a electric move