Defog is a Flying-type move. I just caught some random Zubat and taught it Defog. I didn't want any of my Party Pokémon to have this move. :P
the only REAL reason why one would need it is to fing the dragon lady in one of the foggy areas. I couldn't find a way to her house for such a long time (because i never got defog, thus was not able to see the rock wall) but other than that, you can go without even getting it from the guy in the safari zone.Since Defog is flying-type, use it on a flying pokemon and it should work. Defog's pretty much useless and a crappy combat move unless you really can't see in a foggy area like the area near Celestic town or that one area in Mt. Coronet.
the only REAL reason why one would need it is to fing the dragon lady in one of the foggy areas. I couldn't find a way to her house for such a long time (because i never got defog, thus was not able to see the rock wall) but other than that, you can go without even getting it from the guy in the safari zone.
It should have been made a TM like Flash was. They're both only useful in two small areas of the game that you're not required to visit.
I used it on Staraptor, who was also my Flying pokemon. I'm sure Starly can probably learn it too.